Solvent-Free Green and Efficient One-Pot Synthesis of ...
6
Hindawi Publishing Corporation ISRN Organic Chemistry Volume 2013, Article ID 185120, 5 pages http://dx.doi.org/10.1155/2013/185120 Research Article Solvent-Free Green and Efficient One-Pot Synthesis of Dihydropyrano[3,2-c]chromene Derivatives Shubha Jain, Deepika Rajguru, Balwant S. Keshwal, and Aman D. Acharya School of Studies in Chemistry, Vikram University, Ujjain, Madhya Pradesh 456010, India Correspondence should be addressed to Deepika Rajguru; [email protected] Received 17 June 2013; Accepted 19 August 2013 Academic Editors: M. D’Auria, R. Pohl, D. S´ emeril, and S. B. Wan Copyright © 2013 Shubha Jain et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A rapid, clean, and highly efficient method for synthesis of dihydropyrano[3,2-c]chromene derivatives by one-pot, three-component condensation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin using DABCO as catalyst in solvent-free neat conditions is described. e present method has the advantages of mild reaction conditions, short reaction times, easy isolation of products, and excellent yields. 1. Introduction Multicomponent reactions (MCRs) are very important in organic synthesis due to the formation of carbon-carbon and carbon-hetero atom bonds in one pot [1–3]. Simple procedures, high bond forming efficiency, time and energy saving, and low expenditures are among the advantages of these reactions [4]. Over the past several years, chemists have been aware of the environmental implications of their chemistry. Nowadays, they are trying to develop new syn- thetic methods, reaction conditions, and uses of chemicals that reduce the risks to humans and the environment. Organic solvents are high on the list of hazardous chemicals because they are used in large amounts and are usually volatile liquids. erefore, in recent years, solventless organic reactions have attracted great interest. ey have many advantages such as high efficiency and selectivity, opera- tional simplicity, low costs, mild reaction conditions, and reduced pollution [5–7]. Pyrano[3,2-c]chromenes are a class of important heterocycles with a wide range of biological properties [8] such as spasmolytic, diuretic, anticoagulant, anticancer, and antianaphylactic activity [9]. Moreover, they have been used as cognitive enhancers, for the treatment of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, AIDS associated dementia, and Down’s syndrome as well as for the treatment of schizophrenia and myoclonus [10]. In addition, aminochromene derivatives exhibit a wide spectrum of biological activities including antihypertensive and anti-ischemic behavior [11–13]. Several methods have been reported for the synthesis of pyrano[3,2-c]chromene derivatives. 2-Amino-4-aryl-5-oxo- 4H,5H-pyrano[3,2-c]chromene-3-carbonitriles have previo- usly been prepared from aromatic aldehydes, malono- nitrile, and 4-hydroxycoumarin in the presence of organic bases like piperidine or pyridine in an organic solvent, that is, ethanol and pyridine [14]. ey have also been prepared in the presence of diammonium hydrogen phosphate (DAHP), (S)-proline [15], K 2 CO 3 under microwave irradiation [16], TBAB [17], MgO [18], H 6 P 2 W 18 O 62 ⋅18H 2 O[19], Hexa- methylene tetramine [20], TMGT [21], N,N,N ,N -tetra- bromo benzene-1,3-disulfonamide (TBBDA) and poly(N,N - dibromo-N-ethyl-benzene-1,3-disulfonamide) (PBBS) [22], 3-hydroxypropanaminium acetate (HPAA) [23], 2-hydro- xyethylammonium formate [24], [bmim]Br [25], potassium phthalimide-N-oxyl [26], and CuO nanoparticles [27]. How- ever, some of these methods suffer from the serious limita- tions such as long reaction times, multistep reactions, com- plex synthetic pathways, and lower product yields. erefore, the development of milder, faster, and more ecofriendly methods, accompanied with higher yields is needed. In recent years, 1,4-diazabicyclo[2.2.2]octane (DABCO) has received considerable attention as an inexpensive, eco- friendly, high reactive, easy to handle, and nontoxic base
Transcript of Solvent-Free Green and Efficient One-Pot Synthesis of ...
Hindawi Publishing CorporationISRN Organic ChemistryVolume 2013 Article ID 185120 5 pageshttpdxdoiorg1011552013185120
Research ArticleSolvent-Free Green and Efficient One-Pot Synthesis ofDihydropyrano[32-c]chromene Derivatives
Shubha Jain Deepika Rajguru Balwant S Keshwal and Aman D Acharya
School of Studies in Chemistry Vikram University Ujjain Madhya Pradesh 456010 India
Correspondence should be addressed to Deepika Rajguru deepikarajguru23gmailcom
Received 17 June 2013 Accepted 19 August 2013
Academic Editors M DrsquoAuria R Pohl D Semeril and S B Wan
Copyright copy 2013 Shubha Jain et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
A rapid clean and highly efficientmethod for synthesis of dihydropyrano[32-c]chromene derivatives by one-pot three-componentcondensation of aromatic aldehydes malononitrile and 4-hydroxycoumarin using DABCO as catalyst in solvent-free neatconditions is described The present method has the advantages of mild reaction conditions short reaction times easy isolation ofproducts and excellent yields
1 Introduction
Multicomponent reactions (MCRs) are very important inorganic synthesis due to the formation of carbon-carbonand carbon-hetero atom bonds in one pot [1ndash3] Simpleprocedures high bond forming efficiency time and energysaving and low expenditures are among the advantages ofthese reactions [4] Over the past several years chemistshave been aware of the environmental implications of theirchemistry Nowadays they are trying to develop new syn-thetic methods reaction conditions and uses of chemicalsthat reduce the risks to humans and the environmentOrganic solvents are high on the list of hazardous chemicalsbecause they are used in large amounts and are usuallyvolatile liquidsTherefore in recent years solventless organicreactions have attracted great interest They have manyadvantages such as high efficiency and selectivity opera-tional simplicity low costs mild reaction conditions andreduced pollution [5ndash7] Pyrano[32-c]chromenes are a classof important heterocycles with a wide range of biologicalproperties [8] such as spasmolytic diuretic anticoagulantanticancer and antianaphylactic activity [9] Moreover theyhave been used as cognitive enhancers for the treatment ofneurodegenerative diseases including Alzheimerrsquos diseaseParkinsonrsquos disease Huntingtonrsquos disease amyotrophic lateralsclerosis AIDS associated dementia and Downrsquos syndromeas well as for the treatment of schizophrenia and myoclonus
[10] In addition aminochromene derivatives exhibit a widespectrum of biological activities including antihypertensiveand anti-ischemic behavior [11ndash13]
Several methods have been reported for the synthesis ofpyrano[32-c]chromene derivatives 2-Amino-4-aryl-5-oxo-4H5H-pyrano[32-c]chromene-3-carbonitriles have previo-usly been prepared from aromatic aldehydes malono-nitrile and 4-hydroxycoumarin in the presence of organicbases like piperidine or pyridine in an organic solvent thatis ethanol and pyridine [14]They have also been prepared inthe presence of diammonium hydrogen phosphate (DAHP)(S)-proline [15] K
2CO3under microwave irradiation [16]
TBAB [17] MgO [18] H6P2W18O62sdot18H2O [19] Hexa-
methylene tetramine [20] TMGT [21] NNN1015840N1015840-tetra-bromo benzene-13-disulfonamide (TBBDA) and poly(NN1015840-dibromo-N-ethyl-benzene-13-disulfonamide) (PBBS) [22]3-hydroxypropanaminium acetate (HPAA) [23] 2-hydro-xyethylammonium formate [24] [bmim]Br [25] potassiumphthalimide-N-oxyl [26] and CuO nanoparticles [27] How-ever some of these methods suffer from the serious limita-tions such as long reaction times multistep reactions com-plex synthetic pathways and lower product yieldsThereforethe development of milder faster and more ecofriendlymethods accompanied with higher yields is needed
In recent years 14-diazabicyclo[222]octane (DABCO)has received considerable attention as an inexpensive eco-friendly high reactive easy to handle and nontoxic base
2 ISRN Organic Chemistry
catalyst for various organic transformations affording thecorresponding products in excellent yields with high selectiv-ity [28 29] The reactions are environmentally friendly andthe catalyst can be recycled in some cases In continuationof our interest to further enlarge the application of DABCOas a catalyst [30] here we wish to report one-pot synthesisof pyrano[32-c]chromene derivatives by the reaction ofaromatic aldehydes malononitrile and 4-hydroxycoumarincatalyzed by DABCO in solventless conditions
2 Results and Discussion
When aromatic aldehyde 1 malononitrile 2 and 4-hydroxycoumarin 3 were condensed in the presence of DABCOin solvent-free neat conditions at 100∘C 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromene derivatives 4were obtained in good to high yields (Scheme 1)
In our initial study the reaction of benzaldehyde mal-ononitrile and 4-hydroxycoumarin was used as a modelreaction to optimize the reaction conditions First the reac-tion was conducted in various solvents using DABCO as acatalyst under refluxing conditions and also under solvent-free conditions As can be seen from Table 1 the best resultswere obtained in neatThe effect of temperature in solventlessconditions was studied by carrying out the reaction at 60 80100 and 120∘CThe results fromTable 1 (entry 6) showed that100∘C would be the best temperature for all reactions
Under the optimized reaction conditions a series ofdihydropyrano[32-c]chromene derivatives 4(andashj) were syn-thesized The results are summarized in Table 2 In all casesaromatic aldehydes substituted with either electron-donatingor electron-withdrawing groups underwent the reactionsmoothly and gave the expected products in good to highyields under the same reaction conditions Moreover het-eroaromatic aldehydes could also be successfully convertedto the corresponding heteroaryl substituted pyrano[32-c]chromenes in excellent yields
3 Conclusion
In summary a new clean and efficient protocol for the syn-thesis of pyrano[32-c]chromene derivatives using DABCOunder solvent-free conditions was described The use ofDABCO as a green nontoxic nonexplosive inexpensivenonvolatile easy to handle and thermally stable catalyst withsimple experimental and isolation procedure makes it anattractive method for the preparation of these compounds
4 Experimental
41 General All chemicals were purchased from Merckand Sigma-Aldrich as ldquosynthesis graderdquo and used withoutfurther purification Melting points were determined in openglass capillaries and are uncorrected 1H NMR spectra wereobtained at 400MHz with a Bruker (AVANCE) spectrometerusing DMSO-d
6as solvent and TMS as an internal standard
Elemental analysis was performed using Carlo Erba-1108analyzer
42 General Procedure for the Synthesis of 2-Amino-4-aryl-5-oxo-4H5H-pyrano[32-c]chromene-3-carbonitriles Aroma-tic aldehyde 1 (1mmoL) malononitrile 2 (12mmoL)4-hydroxycoumarin 3 (1mmoL) and DABCO (5moL)were mixed thoroughly and heated in a water bath at 100∘Cfor appropriate time After completion of the reaction(monitored by TLC) the mixture was cooled to roomtemperature The solid product was washed with hot waterdried and recrystallized from ethanol to give the pureproduct
All the compounds were characterized by spectroscopicand physical data which were found to be identical to thosedescribed in the literature
421 2-Amino-5-oxo-4-phenyl-45-dihydropyrano[32-c]chro-mene-3-carbonitrile (4a) White Solid Yield 94 mp256-257∘C (256ndash258∘C) [15] Anal Calcd for C
19H12N2O3 C
7215 H 382 N 886 Found C 7228 H 361 N 8651H-NMR (400MHz DMSO-d
6 120575ppm) 416 (1H s CH)
634 (2H s amino group) 735ndash744 (5H m ArH) 753ndash758(2Hm ArH) 765ndash771 (2Hm ArH) 13C-NMR (400MHzDMSO-d
6 120575ppm) 5327 10362 11338 11583 11601 12132
12314 12353 12485 12508 12712 12837 14135 1527815484 15819 15965
422 2-Amino-4-(4-nitrophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4b) Pale Yellow Solid Yield96 mp 259ndash261∘C (258ndash260∘C) [15] Anal Calcd forC19H11N3O5 C 6316 H 307 N 1163 Found C 6329
H 319 N 1195 1H-NMR (400MHz DMSO-d6 120575ppm)
476 (1H s CH) 643 (2H s amino group) 720ndash722 (2Hdd 119869119886= 39Hz 119869
119887= 10Hz ArH) 727 (1H s ArH) 742
(1H d J = 36Hz ArH) 763ndash765 (1H dd 119869119886= 42Hz 119869
119887
= 09Hz ArH) 769 (1H d J = 37Hz ArH) 776 (2H dJ = 12Hz ArH) 13C-NMR (400MHz DMSO-d
6 120575ppm)
5734 10583 11256 11591 11673 11926 12206 12312 1254912664 12903 13823 14839 15284 15317 15835 15946
423 2-Amino-4-(3-nitrophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4c) White Solid Yield93 mp 261ndash263∘C (262ndash264∘C) [15] Anal Calcd forC19H11N3O5 C 6316 H 307 N 1163 Found C 6328
H 317 N 1196 1H-NMR (400MHz DMSO-d6 120575ppm)
426 (1H s CH) 632 (2H s amino group) 715ndash724 (3Hm ArH) 746 (2H d J = 76Hz ArH) 790 (1H d J =20Hz ArH) 833 (1H d J = 76Hz ArH) 887 (1H s ArH)13C-NMR (400MHz DMSO-d
6 120575ppm) 5537 10758
11335 11519 11624 11973 12252 12365 12554 1287312946 13548 14836 15211 15372 15802 15978
424 2-Amino-4-(4-chlorophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4d) White Solid Yield92 mp 264ndash267∘C (263ndash265∘C) [15] Anal Calcd forC19H11ClN2O3 C 6506 H 316 N 799 Found C 6535
H 326 N 773 1H-NMR (400MHz DMSO-d6 120575ppm)
472 (1H s CH) 674 (2H s amino group) 722 (1H t J =46Hz ArH) 770ndash773 (3Hm ArH) 784 (2H d J = 86HzArH) 836 (2H d J = 86Hz ArH) 13C-NMR (400MHz
ISRN Organic Chemistry 3
ArCHO
O ONeat
O
O
O
2 3
NH2
1(andashj) 4(andashj)
CN
CN
CN
OH
++ ArDABCO (5 mol)
Scheme 1
Table 1 DABCO catalyzed synthesis of 4a in different reactionconditions
Entry Solvent 119879∘C Timeh Yielda1 EtOH Reflux 2 852 CH2Cl2 Reflux 6 543 CH3CN Reflux 4 734 THF Reflux 4 625 H2O Reflux 15 876 mdash 100 05 947 mdash 60 2 658 mdash 80 1 769 mdash 120 05 9210b mdash 100 2 6511c mdash 100 05 95aIsolated yieldb1mol of catalyst was usedc10mol of catalyst was used
DMSO-d6 120575ppm) 5472 10643 11278 11562 11658 11932
12109 12345 12464 12592 12853 13432 13810 1521815297 15849 15956
425 2-Amino-4-(4-bromophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4e) White Solid Yield91 mp 247ndash250∘C (249ndash251∘C) [15] Anal Calcd forC19H11BrN2O3 C 5774 H 281 N 709 Found C 5753
H 296 N 717 1H-NMR (400MHz DMSO-d6 120575ppm)
436 (1H s CH) 660 (2H s amino group) 744 (2H d J= 35Hz ArH) 777 (1H d J = 17Hz ArH) 782ndash784 (3Hm ArH) 836ndash838 (2H dd 119869
119886= 49Hz 119869
119887= 19Hz ArH)
13C-NMR (400MHz DMSO-d6 120575ppm) 5543 10557
11258 11523 11662 11982 12108 12342 12478 1265612758 13645 13934 15249 15284 15737 15989
426 2-Amino-4-(4-methoxyphenyl)-5-oxo-45-dihydropyra-no[32-c]chromene-3-carbonitrile (4f) White Solid Yield89 mp 241ndash244∘C (240ndash242∘C) [15] Anal Calcd forC20H14N2O4 C 6936 H 407 N 809 Found C 6892
H 420 N 819 1H-NMR (400MHz DMSO-d6 120575ppm)
376 (3H s OCH3) 513 (1H s CH) 636 (2H s amino
group) 665-666 (2H q J = 17Hz ArH) 741 (2H d J =33Hz ArH) 757 (2Hm ArH) 775 (2H d J = 15Hz ArH)13C-NMR (400MHzDMSO-d
6 120575ppm) 5295 5766 10390
11296 11626 11739 11928 12249 12372 12432 1252612651 13242 13810 15201 15295 15824 15953
427 2-Amino-5-oxo-4-p-tolyl-45-dihydropyrano[32-c]chro-mene-3-carbonitrile (4g) White Solid Yield 87 mp 252ndash254∘C (250ndash252∘C) [15] Anal Calcd for C
20H14N2O3 C
7272 H 427 N 848 Found C 7246 H 419 N 8581H-NMR (400MHz DMSO-d
6 120575ppm) 210 (3H s CH
3)
458 (1H s CH) 673 (2H s amino group) 722ndash724 (4Hm ArH) 770-771 (2H dd 119869
119886= 27Hz 119869
119887= 10Hz ArH)
774ndash776 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH) 3C-NMR
(400MHz DMSO-d6 120575ppm) 1395 3057 5559 10164
11165 11292 11624 11888 12244 12420 13247 1469115086 15193 15208 15390 15874 15935
428 2-Amino-4-(24-dichlorophenyl)-5-oxo-45-dihydropyr-ano[32-c]chromene-3-carbonitrile (4h) White Solid Yield90 mp 256ndash258∘C (257ndash259∘C) [15] Anal Calcd forC19H10Cl2N2O3 C 5924 H 262 N 727 Found C 5951
H 249 N 748 1H-NMR (400MHz DMSO-d6 120575ppm)
424 (1H s CH) 631 (2H s amino group) 666 (1H dJ = 31Hz ArH) 671 (1H t J = 14Hz ArH) 730 (1Hd J = 32Hz ArH) 759 (2H m ArH) 785 (1H s ArH)795 (1H d J = 09Hz ArH) 13C-NMR (400MHz DMSO-d6 120575ppm) 2838 5799 10405 11336 11597 11619 11936
12050 12240 12338 12423 12534 12715 13226 1350315195 15277 15815 15953
429 2-Amino-4-(furan-2-yl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4i) BrownSolid Yield 97mp251ndash254∘C (252-253∘C) [16] Anal Calcd for C
17H10N2O4 C
6667 H 329 N 915 Found C 6695 H 307 N 9271H-NMR (400MHz DMSO-d
6 120575ppm) 392 (1H s CH)
630 (2H s amino group) 679ndash681 (1H dd 119869119886= 49Hz
119869
119887= 18Hz furan ring) 708ndash712 (3H m furan ring+ArH)
738ndash741 (1H dd 119869119886= 34Hz 119869
119887= 16Hz ArH) 775 (1H d
J = 25Hz ArH) 786 (1H d J = 47Hz ArH) 13C-NMR(400MHz DMSO-d
6 120575ppm) 3049 5587 10164 10616
10698 11155 11290 11617 11886 12244 12411 15092 1516715205 15394 15871 15950
4210 2-Amino-5-oxo-4-(thiophen-2-yl)-45-dihydropyrano-[32-c]chromene-3-carbonitrile (4j) White Solid Yield 96mp 226ndash230∘C (228∘C) [20] Anal Calcd for C
17H10N2O3S
C 6334 H 313 N 869 S 995 Found C 6353 H 324 N837 S 968 1H-NMR (400MHz DMSO-d
6 120575ppm) 494
(1H s CH) 654 (2H s amino group) 698 (1Hm thiophenering) 720ndash722 (2H dd 119869
119886= 38Hz 119869
119887= 13Hz thiophene
ring) 765ndash767 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH)
769-770 (2H dd 119869119886= 26Hz 119869
119887= 11 Hz ArH) 13C-NMR
4 ISRN Organic Chemistry
Table 2 Synthesis of 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromenes in solvent-free neat conditions using DABCO(5mol) as catalyst
Entry Ar Product Timemin Yield mp∘C Found (reported)1 C6H5 4a 30 94 256-257 (256ndash258) [15]2 4-O2N C6H4 4b 30 96 259ndash261 (258ndash260) [15]3 3-O2N C6H4 4c 30 93 261ndash263 (262ndash264) [15]4 4-ClC6H4 4d 30 92 264ndash267 (263ndash265) [15]5 4-BrC6H4 4e 30 91 247ndash250 (249ndash251) [15]6 4-CH3OC6H4 4f 30 89 241ndash244 (240ndash242) [15]7 4-CH3C6H4 4g 30 87 252ndash254 (250ndash252) [15]8 24-Cl2C6H3 4h 30 90 256ndash258 (257ndash259) [15]
9
O
4i 30 97 251ndash254 (252-253) [16]
10
S
4j 30 96 226ndash230 (228) [20]
(400MHz DMSO-d6 120575ppm) 3194 5784 10397 11622
11894 12251 12427 12458 12467 12772 13252 1384114090 15295 15384 15840 15949
Acknowledgment
The authors thank the director of SAIF Punjab UniversityChandigarh for NMR spectral data
References
[1] A Domling ldquoRecent developments in isocyanide based multi-component reactions in applied chemistryrdquo Chemical Reviewsvol 106 no 1 pp 17ndash89 2006
[2] I Ugi ldquoMulticomponent reactions (MCR) Perspectives of mul-ticomponent reactions and their librariesrdquo Advanced SynthesisandCatalysis vol 339 no 1 pp 499ndash516 1997
[3] N K Terrett M Gardner D W Gordon R J Kobylecki andJ Steele ldquoCombinatorial synthesismdashthe design of compoundlibraries and their application to drug discoveryrdquo Tetrahedronvol 51 no 30 pp 8135ndash8173 1995
[4] A Domling and I Ugi ldquoMulticomponent reactions with iso-cyanidesrdquo Angewandte Chemie vol 39 no 18 pp 3168ndash32102000
[5] K Tanaka and F Toda ldquoSolvent-free organic synthesisrdquo Chem-ical Reviews vol 100 no 3 pp 1025ndash1074 2000
[6] F Shirini K Marjani and H T Nahzomi ldquoSilica triflateas an efficient catalyst for the solvent-free synthesis of 34-dihydropyrimidin-2(1H)-onesrdquo Arkivoc vol 2007 no 1 pp 51ndash57 2007
[7] GThirunarayanan and G Vanangamudi ldquoSynthesis of some 4-bromo-1-naphthyl chalcones using silica-sulfuric acid reagentunder solvent free conditionsrdquoArkivoc vol 2006 no 12 pp 58ndash64 2006
[8] G R Green J M Evans A K Vong A R Katritzky C WRees and E F Scriven ldquoPyrans and their benzo derivativessynthesisrdquo in Comprehensive Heterocyclic Chemistry II vol 5 p469 Pergamon Press Oxford UK 1995
[9] W O Foye Principi Di Chemico Frmaceutica Piccin PadovaItaly 1991
[10] C S Konkoy D B Fick S X Cai N C Lan and J F W KeanaldquoPCT international application WO0075123 (2000)rdquo ChemicalAbstracts vol 134 Article ID 29313a 2001
[11] A Burgard H Lang and U Gerlach ldquoAsymmetric synthesis of4-amino-34-dihydro-22-dimethyl-2H-1 benzopyransrdquo Tetra-hedron vol 55 no 24 pp 7555ndash7562 1999
[12] J M Evans C S Fake T C Hamilton R H Poyserand G A Showell ldquoSynthesis and antihypertensive activityof 67-disubstituted trans-4-amino-34-dihydro-22-dimethyl-2H-1-benzopyran-3-olsrdquo Journal ofMedicinal Chemistry vol 27no 9 pp 1127ndash1131 1984
[13] J M Evans C S Fake T C Hamilton R H Poyserand E A Watts ldquoSynthesis and antihypertensive activityof substituted trans-4-amino-34-dihydro-22-dimethyl-2H-l-benzopyran-3-olsrdquo Journal of Medicinal Chemistry vol 26 no11 pp 1582ndash1589 1983
[14] R M Shaker ldquoSynthesis and reactions of some new 4H-pyrano[32-c]benzopyran-5-one derivatives and their potentialbiological activitiesrdquo Pharmazie vol 51 no 3 pp 148ndash151 1996
[15] A S Mohammadi and S Balalaie ldquoNovel and efficient catalystsfor the one-pot synthesis of 34-dihydropyrano[c]chromenederivatives in aqueous mediardquo Tetrahedron Letters vol 48 pp3299ndash3303 2007
[16] M Kidwai and S Saxena ldquoConvenient preparation of pyranobenzopyranes in aqueous mediardquo Synthetic Communicationsvol 36 no 18 pp 2737ndash2742 2006
[17] J M Khurana and S Kumar ldquoTetrabutylammonium bromide(TBAB) a neutral and efficient catalyst for the synthesis ofbiscoumarin and 34-dihydropyrano[c]chromene derivatives in
ISRN Organic Chemistry 5
water and solvent-free conditionsrdquo Tetrahedron Letters vol 50no 28 pp 4125ndash4127 2009
[18] M Seifi and H Sheibani ldquoHigh surface area MgO as ahighly effective heterogeneous base catalyst for three-component synthesis of tetrahydrobenzopyran and 34-dihydropyrano[c]chromene derivatives in aqueous mediardquoCatalysis Letters vol 126 no 3-4 pp 275ndash279 2008
[19] M M Heravi B A Jani F Derikvand F F Bamoharramand H A Oskooie ldquoThree component one-pot synthesisof dihydropyrano[32-c]chromene derivatives in the presenceof H6P2W18O62sdot 18H
2O as a green and recyclable catalystrdquo
Catalysis Communications vol 10 no 3 pp 272ndash275 2008[20] H J Wang J Lu and Z H Zhang ldquoHighly efficient
three-component one-pot synthesis of dihydropyrano[32-c]chromene derivativesrdquo Monatshefte fur Chemie vol 141 no10 pp 1107ndash1112 2010
[21] A Shaabani S Samadi Z Badri and A Rahmati ldquoIonicliquid promoted efficient and rapid one-pot synthesis of pyranannulated heterocyclic systemsrdquo Catalysis Letters vol 104 no1-2 pp 39ndash43 2005
[22] G V Ramin T S Zahra andKN Rahman ldquoOne-pot synthesisof 4H-Chromene and Dihydropyrano[32-c]chromene deriva-tives in hydroalcoholicmediardquo Journal of the Brazilian ChemicalSociety vol 22 no 5 pp 905ndash909 2011
[23] H R Shaterian and A R Oveisi ldquoA simple Green approachto the synthesis of 2-amino-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile derivatives catalyzed by 3-hydroxypropanaminium acetate (HPAA) as a new ionicliquidrdquo Journal of the Iranian Chemical Society vol 8 no 2 pp545ndash552 2011
[24] H R Shaterian M Arman and F Rigi ldquoDomino Knoevenagelcondensation Michael addition and cyclization using ionicliquid 2-hydroxyethylammonium formate as a recoverablecatalystrdquo Journal of Molecular Liquids vol 158 no 2 pp 145ndash150 2011
[25] N Tavakoli-Hoseini M M Heravi F F Bamoharram andA Davoodnia ldquoGreen catalyst-free protocol for synthesis ofdihydropyrano[32-c] chromenes in ionic liquid [bmim]Br as anefficient promoting mediumrdquo Asian Journal of Chemistry vol23 no 8 pp 3599ndash3601 2011
[26] M G Dekamin M Eslami and A Maleki ldquoPotassiumphthalimide-N-oxyl a novel efficient and simple organocat-alyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in waterrdquo Tetrahedron vol 69no 3 pp 1074ndash1085 2013
[27] MHossein andKMMaryam ldquoCuOnanoparticles an efficientand recyclable nanocatalyst for the rapid and green synthesisof 34-dihydropyrano[c]chromenesrdquo Chinese Chemical Lettersvol 22 no 12 pp 1419ndash1422 2011
[28] H Yang R Tian and Y Li ldquoOrganic reactions catalyzed by 14-diazabicyclo [222] octane (DABCO)rdquo Frontiers of Chemistryin China vol 3 no 3 pp 279ndash287 2008
[29] B Baghernejad ldquo14-Diazabicyclo[222]octane (DABCO) asa useful catalyst in organic synthesisrdquo European Journal ofChemistry vol 1 no 1 pp 54ndash60 2010
[30] P Paliwal S R Jetti A Bhatewara et al ldquoDABCO catalyzedsynthesis of Xanthene derivatives in aqueous mediardquo ISRNOrganic Chemistry vol 2013 Article ID 526173 6 pages 2013
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
2 ISRN Organic Chemistry
catalyst for various organic transformations affording thecorresponding products in excellent yields with high selectiv-ity [28 29] The reactions are environmentally friendly andthe catalyst can be recycled in some cases In continuationof our interest to further enlarge the application of DABCOas a catalyst [30] here we wish to report one-pot synthesisof pyrano[32-c]chromene derivatives by the reaction ofaromatic aldehydes malononitrile and 4-hydroxycoumarincatalyzed by DABCO in solventless conditions
2 Results and Discussion
When aromatic aldehyde 1 malononitrile 2 and 4-hydroxycoumarin 3 were condensed in the presence of DABCOin solvent-free neat conditions at 100∘C 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromene derivatives 4were obtained in good to high yields (Scheme 1)
In our initial study the reaction of benzaldehyde mal-ononitrile and 4-hydroxycoumarin was used as a modelreaction to optimize the reaction conditions First the reac-tion was conducted in various solvents using DABCO as acatalyst under refluxing conditions and also under solvent-free conditions As can be seen from Table 1 the best resultswere obtained in neatThe effect of temperature in solventlessconditions was studied by carrying out the reaction at 60 80100 and 120∘CThe results fromTable 1 (entry 6) showed that100∘C would be the best temperature for all reactions
Under the optimized reaction conditions a series ofdihydropyrano[32-c]chromene derivatives 4(andashj) were syn-thesized The results are summarized in Table 2 In all casesaromatic aldehydes substituted with either electron-donatingor electron-withdrawing groups underwent the reactionsmoothly and gave the expected products in good to highyields under the same reaction conditions Moreover het-eroaromatic aldehydes could also be successfully convertedto the corresponding heteroaryl substituted pyrano[32-c]chromenes in excellent yields
3 Conclusion
In summary a new clean and efficient protocol for the syn-thesis of pyrano[32-c]chromene derivatives using DABCOunder solvent-free conditions was described The use ofDABCO as a green nontoxic nonexplosive inexpensivenonvolatile easy to handle and thermally stable catalyst withsimple experimental and isolation procedure makes it anattractive method for the preparation of these compounds
4 Experimental
41 General All chemicals were purchased from Merckand Sigma-Aldrich as ldquosynthesis graderdquo and used withoutfurther purification Melting points were determined in openglass capillaries and are uncorrected 1H NMR spectra wereobtained at 400MHz with a Bruker (AVANCE) spectrometerusing DMSO-d
6as solvent and TMS as an internal standard
Elemental analysis was performed using Carlo Erba-1108analyzer
42 General Procedure for the Synthesis of 2-Amino-4-aryl-5-oxo-4H5H-pyrano[32-c]chromene-3-carbonitriles Aroma-tic aldehyde 1 (1mmoL) malononitrile 2 (12mmoL)4-hydroxycoumarin 3 (1mmoL) and DABCO (5moL)were mixed thoroughly and heated in a water bath at 100∘Cfor appropriate time After completion of the reaction(monitored by TLC) the mixture was cooled to roomtemperature The solid product was washed with hot waterdried and recrystallized from ethanol to give the pureproduct
All the compounds were characterized by spectroscopicand physical data which were found to be identical to thosedescribed in the literature
421 2-Amino-5-oxo-4-phenyl-45-dihydropyrano[32-c]chro-mene-3-carbonitrile (4a) White Solid Yield 94 mp256-257∘C (256ndash258∘C) [15] Anal Calcd for C
19H12N2O3 C
7215 H 382 N 886 Found C 7228 H 361 N 8651H-NMR (400MHz DMSO-d
6 120575ppm) 416 (1H s CH)
634 (2H s amino group) 735ndash744 (5H m ArH) 753ndash758(2Hm ArH) 765ndash771 (2Hm ArH) 13C-NMR (400MHzDMSO-d
6 120575ppm) 5327 10362 11338 11583 11601 12132
12314 12353 12485 12508 12712 12837 14135 1527815484 15819 15965
422 2-Amino-4-(4-nitrophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4b) Pale Yellow Solid Yield96 mp 259ndash261∘C (258ndash260∘C) [15] Anal Calcd forC19H11N3O5 C 6316 H 307 N 1163 Found C 6329
H 319 N 1195 1H-NMR (400MHz DMSO-d6 120575ppm)
476 (1H s CH) 643 (2H s amino group) 720ndash722 (2Hdd 119869119886= 39Hz 119869
119887= 10Hz ArH) 727 (1H s ArH) 742
(1H d J = 36Hz ArH) 763ndash765 (1H dd 119869119886= 42Hz 119869
119887
= 09Hz ArH) 769 (1H d J = 37Hz ArH) 776 (2H dJ = 12Hz ArH) 13C-NMR (400MHz DMSO-d
6 120575ppm)
5734 10583 11256 11591 11673 11926 12206 12312 1254912664 12903 13823 14839 15284 15317 15835 15946
423 2-Amino-4-(3-nitrophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4c) White Solid Yield93 mp 261ndash263∘C (262ndash264∘C) [15] Anal Calcd forC19H11N3O5 C 6316 H 307 N 1163 Found C 6328
H 317 N 1196 1H-NMR (400MHz DMSO-d6 120575ppm)
426 (1H s CH) 632 (2H s amino group) 715ndash724 (3Hm ArH) 746 (2H d J = 76Hz ArH) 790 (1H d J =20Hz ArH) 833 (1H d J = 76Hz ArH) 887 (1H s ArH)13C-NMR (400MHz DMSO-d
6 120575ppm) 5537 10758
11335 11519 11624 11973 12252 12365 12554 1287312946 13548 14836 15211 15372 15802 15978
424 2-Amino-4-(4-chlorophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4d) White Solid Yield92 mp 264ndash267∘C (263ndash265∘C) [15] Anal Calcd forC19H11ClN2O3 C 6506 H 316 N 799 Found C 6535
H 326 N 773 1H-NMR (400MHz DMSO-d6 120575ppm)
472 (1H s CH) 674 (2H s amino group) 722 (1H t J =46Hz ArH) 770ndash773 (3Hm ArH) 784 (2H d J = 86HzArH) 836 (2H d J = 86Hz ArH) 13C-NMR (400MHz
ISRN Organic Chemistry 3
ArCHO
O ONeat
O
O
O
2 3
NH2
1(andashj) 4(andashj)
CN
CN
CN
OH
++ ArDABCO (5 mol)
Scheme 1
Table 1 DABCO catalyzed synthesis of 4a in different reactionconditions
Entry Solvent 119879∘C Timeh Yielda1 EtOH Reflux 2 852 CH2Cl2 Reflux 6 543 CH3CN Reflux 4 734 THF Reflux 4 625 H2O Reflux 15 876 mdash 100 05 947 mdash 60 2 658 mdash 80 1 769 mdash 120 05 9210b mdash 100 2 6511c mdash 100 05 95aIsolated yieldb1mol of catalyst was usedc10mol of catalyst was used
DMSO-d6 120575ppm) 5472 10643 11278 11562 11658 11932
12109 12345 12464 12592 12853 13432 13810 1521815297 15849 15956
425 2-Amino-4-(4-bromophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4e) White Solid Yield91 mp 247ndash250∘C (249ndash251∘C) [15] Anal Calcd forC19H11BrN2O3 C 5774 H 281 N 709 Found C 5753
H 296 N 717 1H-NMR (400MHz DMSO-d6 120575ppm)
436 (1H s CH) 660 (2H s amino group) 744 (2H d J= 35Hz ArH) 777 (1H d J = 17Hz ArH) 782ndash784 (3Hm ArH) 836ndash838 (2H dd 119869
119886= 49Hz 119869
119887= 19Hz ArH)
13C-NMR (400MHz DMSO-d6 120575ppm) 5543 10557
11258 11523 11662 11982 12108 12342 12478 1265612758 13645 13934 15249 15284 15737 15989
426 2-Amino-4-(4-methoxyphenyl)-5-oxo-45-dihydropyra-no[32-c]chromene-3-carbonitrile (4f) White Solid Yield89 mp 241ndash244∘C (240ndash242∘C) [15] Anal Calcd forC20H14N2O4 C 6936 H 407 N 809 Found C 6892
H 420 N 819 1H-NMR (400MHz DMSO-d6 120575ppm)
376 (3H s OCH3) 513 (1H s CH) 636 (2H s amino
group) 665-666 (2H q J = 17Hz ArH) 741 (2H d J =33Hz ArH) 757 (2Hm ArH) 775 (2H d J = 15Hz ArH)13C-NMR (400MHzDMSO-d
6 120575ppm) 5295 5766 10390
11296 11626 11739 11928 12249 12372 12432 1252612651 13242 13810 15201 15295 15824 15953
427 2-Amino-5-oxo-4-p-tolyl-45-dihydropyrano[32-c]chro-mene-3-carbonitrile (4g) White Solid Yield 87 mp 252ndash254∘C (250ndash252∘C) [15] Anal Calcd for C
20H14N2O3 C
7272 H 427 N 848 Found C 7246 H 419 N 8581H-NMR (400MHz DMSO-d
6 120575ppm) 210 (3H s CH
3)
458 (1H s CH) 673 (2H s amino group) 722ndash724 (4Hm ArH) 770-771 (2H dd 119869
119886= 27Hz 119869
119887= 10Hz ArH)
774ndash776 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH) 3C-NMR
(400MHz DMSO-d6 120575ppm) 1395 3057 5559 10164
11165 11292 11624 11888 12244 12420 13247 1469115086 15193 15208 15390 15874 15935
428 2-Amino-4-(24-dichlorophenyl)-5-oxo-45-dihydropyr-ano[32-c]chromene-3-carbonitrile (4h) White Solid Yield90 mp 256ndash258∘C (257ndash259∘C) [15] Anal Calcd forC19H10Cl2N2O3 C 5924 H 262 N 727 Found C 5951
H 249 N 748 1H-NMR (400MHz DMSO-d6 120575ppm)
424 (1H s CH) 631 (2H s amino group) 666 (1H dJ = 31Hz ArH) 671 (1H t J = 14Hz ArH) 730 (1Hd J = 32Hz ArH) 759 (2H m ArH) 785 (1H s ArH)795 (1H d J = 09Hz ArH) 13C-NMR (400MHz DMSO-d6 120575ppm) 2838 5799 10405 11336 11597 11619 11936
12050 12240 12338 12423 12534 12715 13226 1350315195 15277 15815 15953
429 2-Amino-4-(furan-2-yl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4i) BrownSolid Yield 97mp251ndash254∘C (252-253∘C) [16] Anal Calcd for C
17H10N2O4 C
6667 H 329 N 915 Found C 6695 H 307 N 9271H-NMR (400MHz DMSO-d
6 120575ppm) 392 (1H s CH)
630 (2H s amino group) 679ndash681 (1H dd 119869119886= 49Hz
119869
119887= 18Hz furan ring) 708ndash712 (3H m furan ring+ArH)
738ndash741 (1H dd 119869119886= 34Hz 119869
119887= 16Hz ArH) 775 (1H d
J = 25Hz ArH) 786 (1H d J = 47Hz ArH) 13C-NMR(400MHz DMSO-d
6 120575ppm) 3049 5587 10164 10616
10698 11155 11290 11617 11886 12244 12411 15092 1516715205 15394 15871 15950
4210 2-Amino-5-oxo-4-(thiophen-2-yl)-45-dihydropyrano-[32-c]chromene-3-carbonitrile (4j) White Solid Yield 96mp 226ndash230∘C (228∘C) [20] Anal Calcd for C
17H10N2O3S
C 6334 H 313 N 869 S 995 Found C 6353 H 324 N837 S 968 1H-NMR (400MHz DMSO-d
6 120575ppm) 494
(1H s CH) 654 (2H s amino group) 698 (1Hm thiophenering) 720ndash722 (2H dd 119869
119886= 38Hz 119869
119887= 13Hz thiophene
ring) 765ndash767 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH)
769-770 (2H dd 119869119886= 26Hz 119869
119887= 11 Hz ArH) 13C-NMR
4 ISRN Organic Chemistry
Table 2 Synthesis of 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromenes in solvent-free neat conditions using DABCO(5mol) as catalyst
Entry Ar Product Timemin Yield mp∘C Found (reported)1 C6H5 4a 30 94 256-257 (256ndash258) [15]2 4-O2N C6H4 4b 30 96 259ndash261 (258ndash260) [15]3 3-O2N C6H4 4c 30 93 261ndash263 (262ndash264) [15]4 4-ClC6H4 4d 30 92 264ndash267 (263ndash265) [15]5 4-BrC6H4 4e 30 91 247ndash250 (249ndash251) [15]6 4-CH3OC6H4 4f 30 89 241ndash244 (240ndash242) [15]7 4-CH3C6H4 4g 30 87 252ndash254 (250ndash252) [15]8 24-Cl2C6H3 4h 30 90 256ndash258 (257ndash259) [15]
9
O
4i 30 97 251ndash254 (252-253) [16]
10
S
4j 30 96 226ndash230 (228) [20]
(400MHz DMSO-d6 120575ppm) 3194 5784 10397 11622
11894 12251 12427 12458 12467 12772 13252 1384114090 15295 15384 15840 15949
Acknowledgment
The authors thank the director of SAIF Punjab UniversityChandigarh for NMR spectral data
References
[1] A Domling ldquoRecent developments in isocyanide based multi-component reactions in applied chemistryrdquo Chemical Reviewsvol 106 no 1 pp 17ndash89 2006
[2] I Ugi ldquoMulticomponent reactions (MCR) Perspectives of mul-ticomponent reactions and their librariesrdquo Advanced SynthesisandCatalysis vol 339 no 1 pp 499ndash516 1997
[3] N K Terrett M Gardner D W Gordon R J Kobylecki andJ Steele ldquoCombinatorial synthesismdashthe design of compoundlibraries and their application to drug discoveryrdquo Tetrahedronvol 51 no 30 pp 8135ndash8173 1995
[4] A Domling and I Ugi ldquoMulticomponent reactions with iso-cyanidesrdquo Angewandte Chemie vol 39 no 18 pp 3168ndash32102000
[5] K Tanaka and F Toda ldquoSolvent-free organic synthesisrdquo Chem-ical Reviews vol 100 no 3 pp 1025ndash1074 2000
[6] F Shirini K Marjani and H T Nahzomi ldquoSilica triflateas an efficient catalyst for the solvent-free synthesis of 34-dihydropyrimidin-2(1H)-onesrdquo Arkivoc vol 2007 no 1 pp 51ndash57 2007
[7] GThirunarayanan and G Vanangamudi ldquoSynthesis of some 4-bromo-1-naphthyl chalcones using silica-sulfuric acid reagentunder solvent free conditionsrdquoArkivoc vol 2006 no 12 pp 58ndash64 2006
[8] G R Green J M Evans A K Vong A R Katritzky C WRees and E F Scriven ldquoPyrans and their benzo derivativessynthesisrdquo in Comprehensive Heterocyclic Chemistry II vol 5 p469 Pergamon Press Oxford UK 1995
[9] W O Foye Principi Di Chemico Frmaceutica Piccin PadovaItaly 1991
[10] C S Konkoy D B Fick S X Cai N C Lan and J F W KeanaldquoPCT international application WO0075123 (2000)rdquo ChemicalAbstracts vol 134 Article ID 29313a 2001
[11] A Burgard H Lang and U Gerlach ldquoAsymmetric synthesis of4-amino-34-dihydro-22-dimethyl-2H-1 benzopyransrdquo Tetra-hedron vol 55 no 24 pp 7555ndash7562 1999
[12] J M Evans C S Fake T C Hamilton R H Poyserand G A Showell ldquoSynthesis and antihypertensive activityof 67-disubstituted trans-4-amino-34-dihydro-22-dimethyl-2H-1-benzopyran-3-olsrdquo Journal ofMedicinal Chemistry vol 27no 9 pp 1127ndash1131 1984
[13] J M Evans C S Fake T C Hamilton R H Poyserand E A Watts ldquoSynthesis and antihypertensive activityof substituted trans-4-amino-34-dihydro-22-dimethyl-2H-l-benzopyran-3-olsrdquo Journal of Medicinal Chemistry vol 26 no11 pp 1582ndash1589 1983
[14] R M Shaker ldquoSynthesis and reactions of some new 4H-pyrano[32-c]benzopyran-5-one derivatives and their potentialbiological activitiesrdquo Pharmazie vol 51 no 3 pp 148ndash151 1996
[15] A S Mohammadi and S Balalaie ldquoNovel and efficient catalystsfor the one-pot synthesis of 34-dihydropyrano[c]chromenederivatives in aqueous mediardquo Tetrahedron Letters vol 48 pp3299ndash3303 2007
[16] M Kidwai and S Saxena ldquoConvenient preparation of pyranobenzopyranes in aqueous mediardquo Synthetic Communicationsvol 36 no 18 pp 2737ndash2742 2006
[17] J M Khurana and S Kumar ldquoTetrabutylammonium bromide(TBAB) a neutral and efficient catalyst for the synthesis ofbiscoumarin and 34-dihydropyrano[c]chromene derivatives in
ISRN Organic Chemistry 5
water and solvent-free conditionsrdquo Tetrahedron Letters vol 50no 28 pp 4125ndash4127 2009
[18] M Seifi and H Sheibani ldquoHigh surface area MgO as ahighly effective heterogeneous base catalyst for three-component synthesis of tetrahydrobenzopyran and 34-dihydropyrano[c]chromene derivatives in aqueous mediardquoCatalysis Letters vol 126 no 3-4 pp 275ndash279 2008
[19] M M Heravi B A Jani F Derikvand F F Bamoharramand H A Oskooie ldquoThree component one-pot synthesisof dihydropyrano[32-c]chromene derivatives in the presenceof H6P2W18O62sdot 18H
2O as a green and recyclable catalystrdquo
Catalysis Communications vol 10 no 3 pp 272ndash275 2008[20] H J Wang J Lu and Z H Zhang ldquoHighly efficient
three-component one-pot synthesis of dihydropyrano[32-c]chromene derivativesrdquo Monatshefte fur Chemie vol 141 no10 pp 1107ndash1112 2010
[21] A Shaabani S Samadi Z Badri and A Rahmati ldquoIonicliquid promoted efficient and rapid one-pot synthesis of pyranannulated heterocyclic systemsrdquo Catalysis Letters vol 104 no1-2 pp 39ndash43 2005
[22] G V Ramin T S Zahra andKN Rahman ldquoOne-pot synthesisof 4H-Chromene and Dihydropyrano[32-c]chromene deriva-tives in hydroalcoholicmediardquo Journal of the Brazilian ChemicalSociety vol 22 no 5 pp 905ndash909 2011
[23] H R Shaterian and A R Oveisi ldquoA simple Green approachto the synthesis of 2-amino-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile derivatives catalyzed by 3-hydroxypropanaminium acetate (HPAA) as a new ionicliquidrdquo Journal of the Iranian Chemical Society vol 8 no 2 pp545ndash552 2011
[24] H R Shaterian M Arman and F Rigi ldquoDomino Knoevenagelcondensation Michael addition and cyclization using ionicliquid 2-hydroxyethylammonium formate as a recoverablecatalystrdquo Journal of Molecular Liquids vol 158 no 2 pp 145ndash150 2011
[25] N Tavakoli-Hoseini M M Heravi F F Bamoharram andA Davoodnia ldquoGreen catalyst-free protocol for synthesis ofdihydropyrano[32-c] chromenes in ionic liquid [bmim]Br as anefficient promoting mediumrdquo Asian Journal of Chemistry vol23 no 8 pp 3599ndash3601 2011
[26] M G Dekamin M Eslami and A Maleki ldquoPotassiumphthalimide-N-oxyl a novel efficient and simple organocat-alyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in waterrdquo Tetrahedron vol 69no 3 pp 1074ndash1085 2013
[27] MHossein andKMMaryam ldquoCuOnanoparticles an efficientand recyclable nanocatalyst for the rapid and green synthesisof 34-dihydropyrano[c]chromenesrdquo Chinese Chemical Lettersvol 22 no 12 pp 1419ndash1422 2011
[28] H Yang R Tian and Y Li ldquoOrganic reactions catalyzed by 14-diazabicyclo [222] octane (DABCO)rdquo Frontiers of Chemistryin China vol 3 no 3 pp 279ndash287 2008
[29] B Baghernejad ldquo14-Diazabicyclo[222]octane (DABCO) asa useful catalyst in organic synthesisrdquo European Journal ofChemistry vol 1 no 1 pp 54ndash60 2010
[30] P Paliwal S R Jetti A Bhatewara et al ldquoDABCO catalyzedsynthesis of Xanthene derivatives in aqueous mediardquo ISRNOrganic Chemistry vol 2013 Article ID 526173 6 pages 2013
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
ISRN Organic Chemistry 3
ArCHO
O ONeat
O
O
O
2 3
NH2
1(andashj) 4(andashj)
CN
CN
CN
OH
++ ArDABCO (5 mol)
Scheme 1
Table 1 DABCO catalyzed synthesis of 4a in different reactionconditions
Entry Solvent 119879∘C Timeh Yielda1 EtOH Reflux 2 852 CH2Cl2 Reflux 6 543 CH3CN Reflux 4 734 THF Reflux 4 625 H2O Reflux 15 876 mdash 100 05 947 mdash 60 2 658 mdash 80 1 769 mdash 120 05 9210b mdash 100 2 6511c mdash 100 05 95aIsolated yieldb1mol of catalyst was usedc10mol of catalyst was used
DMSO-d6 120575ppm) 5472 10643 11278 11562 11658 11932
12109 12345 12464 12592 12853 13432 13810 1521815297 15849 15956
425 2-Amino-4-(4-bromophenyl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4e) White Solid Yield91 mp 247ndash250∘C (249ndash251∘C) [15] Anal Calcd forC19H11BrN2O3 C 5774 H 281 N 709 Found C 5753
H 296 N 717 1H-NMR (400MHz DMSO-d6 120575ppm)
436 (1H s CH) 660 (2H s amino group) 744 (2H d J= 35Hz ArH) 777 (1H d J = 17Hz ArH) 782ndash784 (3Hm ArH) 836ndash838 (2H dd 119869
119886= 49Hz 119869
119887= 19Hz ArH)
13C-NMR (400MHz DMSO-d6 120575ppm) 5543 10557
11258 11523 11662 11982 12108 12342 12478 1265612758 13645 13934 15249 15284 15737 15989
426 2-Amino-4-(4-methoxyphenyl)-5-oxo-45-dihydropyra-no[32-c]chromene-3-carbonitrile (4f) White Solid Yield89 mp 241ndash244∘C (240ndash242∘C) [15] Anal Calcd forC20H14N2O4 C 6936 H 407 N 809 Found C 6892
H 420 N 819 1H-NMR (400MHz DMSO-d6 120575ppm)
376 (3H s OCH3) 513 (1H s CH) 636 (2H s amino
group) 665-666 (2H q J = 17Hz ArH) 741 (2H d J =33Hz ArH) 757 (2Hm ArH) 775 (2H d J = 15Hz ArH)13C-NMR (400MHzDMSO-d
6 120575ppm) 5295 5766 10390
11296 11626 11739 11928 12249 12372 12432 1252612651 13242 13810 15201 15295 15824 15953
427 2-Amino-5-oxo-4-p-tolyl-45-dihydropyrano[32-c]chro-mene-3-carbonitrile (4g) White Solid Yield 87 mp 252ndash254∘C (250ndash252∘C) [15] Anal Calcd for C
20H14N2O3 C
7272 H 427 N 848 Found C 7246 H 419 N 8581H-NMR (400MHz DMSO-d
6 120575ppm) 210 (3H s CH
3)
458 (1H s CH) 673 (2H s amino group) 722ndash724 (4Hm ArH) 770-771 (2H dd 119869
119886= 27Hz 119869
119887= 10Hz ArH)
774ndash776 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH) 3C-NMR
(400MHz DMSO-d6 120575ppm) 1395 3057 5559 10164
11165 11292 11624 11888 12244 12420 13247 1469115086 15193 15208 15390 15874 15935
428 2-Amino-4-(24-dichlorophenyl)-5-oxo-45-dihydropyr-ano[32-c]chromene-3-carbonitrile (4h) White Solid Yield90 mp 256ndash258∘C (257ndash259∘C) [15] Anal Calcd forC19H10Cl2N2O3 C 5924 H 262 N 727 Found C 5951
H 249 N 748 1H-NMR (400MHz DMSO-d6 120575ppm)
424 (1H s CH) 631 (2H s amino group) 666 (1H dJ = 31Hz ArH) 671 (1H t J = 14Hz ArH) 730 (1Hd J = 32Hz ArH) 759 (2H m ArH) 785 (1H s ArH)795 (1H d J = 09Hz ArH) 13C-NMR (400MHz DMSO-d6 120575ppm) 2838 5799 10405 11336 11597 11619 11936
12050 12240 12338 12423 12534 12715 13226 1350315195 15277 15815 15953
429 2-Amino-4-(furan-2-yl)-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile (4i) BrownSolid Yield 97mp251ndash254∘C (252-253∘C) [16] Anal Calcd for C
17H10N2O4 C
6667 H 329 N 915 Found C 6695 H 307 N 9271H-NMR (400MHz DMSO-d
6 120575ppm) 392 (1H s CH)
630 (2H s amino group) 679ndash681 (1H dd 119869119886= 49Hz
119869
119887= 18Hz furan ring) 708ndash712 (3H m furan ring+ArH)
738ndash741 (1H dd 119869119886= 34Hz 119869
119887= 16Hz ArH) 775 (1H d
J = 25Hz ArH) 786 (1H d J = 47Hz ArH) 13C-NMR(400MHz DMSO-d
6 120575ppm) 3049 5587 10164 10616
10698 11155 11290 11617 11886 12244 12411 15092 1516715205 15394 15871 15950
4210 2-Amino-5-oxo-4-(thiophen-2-yl)-45-dihydropyrano-[32-c]chromene-3-carbonitrile (4j) White Solid Yield 96mp 226ndash230∘C (228∘C) [20] Anal Calcd for C
17H10N2O3S
C 6334 H 313 N 869 S 995 Found C 6353 H 324 N837 S 968 1H-NMR (400MHz DMSO-d
6 120575ppm) 494
(1H s CH) 654 (2H s amino group) 698 (1Hm thiophenering) 720ndash722 (2H dd 119869
119886= 38Hz 119869
119887= 13Hz thiophene
ring) 765ndash767 (2H dd 119869119886= 42Hz 119869
119887= 10Hz ArH)
769-770 (2H dd 119869119886= 26Hz 119869
119887= 11 Hz ArH) 13C-NMR
4 ISRN Organic Chemistry
Table 2 Synthesis of 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromenes in solvent-free neat conditions using DABCO(5mol) as catalyst
Entry Ar Product Timemin Yield mp∘C Found (reported)1 C6H5 4a 30 94 256-257 (256ndash258) [15]2 4-O2N C6H4 4b 30 96 259ndash261 (258ndash260) [15]3 3-O2N C6H4 4c 30 93 261ndash263 (262ndash264) [15]4 4-ClC6H4 4d 30 92 264ndash267 (263ndash265) [15]5 4-BrC6H4 4e 30 91 247ndash250 (249ndash251) [15]6 4-CH3OC6H4 4f 30 89 241ndash244 (240ndash242) [15]7 4-CH3C6H4 4g 30 87 252ndash254 (250ndash252) [15]8 24-Cl2C6H3 4h 30 90 256ndash258 (257ndash259) [15]
9
O
4i 30 97 251ndash254 (252-253) [16]
10
S
4j 30 96 226ndash230 (228) [20]
(400MHz DMSO-d6 120575ppm) 3194 5784 10397 11622
11894 12251 12427 12458 12467 12772 13252 1384114090 15295 15384 15840 15949
Acknowledgment
The authors thank the director of SAIF Punjab UniversityChandigarh for NMR spectral data
References
[1] A Domling ldquoRecent developments in isocyanide based multi-component reactions in applied chemistryrdquo Chemical Reviewsvol 106 no 1 pp 17ndash89 2006
[2] I Ugi ldquoMulticomponent reactions (MCR) Perspectives of mul-ticomponent reactions and their librariesrdquo Advanced SynthesisandCatalysis vol 339 no 1 pp 499ndash516 1997
[3] N K Terrett M Gardner D W Gordon R J Kobylecki andJ Steele ldquoCombinatorial synthesismdashthe design of compoundlibraries and their application to drug discoveryrdquo Tetrahedronvol 51 no 30 pp 8135ndash8173 1995
[4] A Domling and I Ugi ldquoMulticomponent reactions with iso-cyanidesrdquo Angewandte Chemie vol 39 no 18 pp 3168ndash32102000
[5] K Tanaka and F Toda ldquoSolvent-free organic synthesisrdquo Chem-ical Reviews vol 100 no 3 pp 1025ndash1074 2000
[6] F Shirini K Marjani and H T Nahzomi ldquoSilica triflateas an efficient catalyst for the solvent-free synthesis of 34-dihydropyrimidin-2(1H)-onesrdquo Arkivoc vol 2007 no 1 pp 51ndash57 2007
[7] GThirunarayanan and G Vanangamudi ldquoSynthesis of some 4-bromo-1-naphthyl chalcones using silica-sulfuric acid reagentunder solvent free conditionsrdquoArkivoc vol 2006 no 12 pp 58ndash64 2006
[8] G R Green J M Evans A K Vong A R Katritzky C WRees and E F Scriven ldquoPyrans and their benzo derivativessynthesisrdquo in Comprehensive Heterocyclic Chemistry II vol 5 p469 Pergamon Press Oxford UK 1995
[9] W O Foye Principi Di Chemico Frmaceutica Piccin PadovaItaly 1991
[10] C S Konkoy D B Fick S X Cai N C Lan and J F W KeanaldquoPCT international application WO0075123 (2000)rdquo ChemicalAbstracts vol 134 Article ID 29313a 2001
[11] A Burgard H Lang and U Gerlach ldquoAsymmetric synthesis of4-amino-34-dihydro-22-dimethyl-2H-1 benzopyransrdquo Tetra-hedron vol 55 no 24 pp 7555ndash7562 1999
[12] J M Evans C S Fake T C Hamilton R H Poyserand G A Showell ldquoSynthesis and antihypertensive activityof 67-disubstituted trans-4-amino-34-dihydro-22-dimethyl-2H-1-benzopyran-3-olsrdquo Journal ofMedicinal Chemistry vol 27no 9 pp 1127ndash1131 1984
[13] J M Evans C S Fake T C Hamilton R H Poyserand E A Watts ldquoSynthesis and antihypertensive activityof substituted trans-4-amino-34-dihydro-22-dimethyl-2H-l-benzopyran-3-olsrdquo Journal of Medicinal Chemistry vol 26 no11 pp 1582ndash1589 1983
[14] R M Shaker ldquoSynthesis and reactions of some new 4H-pyrano[32-c]benzopyran-5-one derivatives and their potentialbiological activitiesrdquo Pharmazie vol 51 no 3 pp 148ndash151 1996
[15] A S Mohammadi and S Balalaie ldquoNovel and efficient catalystsfor the one-pot synthesis of 34-dihydropyrano[c]chromenederivatives in aqueous mediardquo Tetrahedron Letters vol 48 pp3299ndash3303 2007
[16] M Kidwai and S Saxena ldquoConvenient preparation of pyranobenzopyranes in aqueous mediardquo Synthetic Communicationsvol 36 no 18 pp 2737ndash2742 2006
[17] J M Khurana and S Kumar ldquoTetrabutylammonium bromide(TBAB) a neutral and efficient catalyst for the synthesis ofbiscoumarin and 34-dihydropyrano[c]chromene derivatives in
ISRN Organic Chemistry 5
water and solvent-free conditionsrdquo Tetrahedron Letters vol 50no 28 pp 4125ndash4127 2009
[18] M Seifi and H Sheibani ldquoHigh surface area MgO as ahighly effective heterogeneous base catalyst for three-component synthesis of tetrahydrobenzopyran and 34-dihydropyrano[c]chromene derivatives in aqueous mediardquoCatalysis Letters vol 126 no 3-4 pp 275ndash279 2008
[19] M M Heravi B A Jani F Derikvand F F Bamoharramand H A Oskooie ldquoThree component one-pot synthesisof dihydropyrano[32-c]chromene derivatives in the presenceof H6P2W18O62sdot 18H
2O as a green and recyclable catalystrdquo
Catalysis Communications vol 10 no 3 pp 272ndash275 2008[20] H J Wang J Lu and Z H Zhang ldquoHighly efficient
three-component one-pot synthesis of dihydropyrano[32-c]chromene derivativesrdquo Monatshefte fur Chemie vol 141 no10 pp 1107ndash1112 2010
[21] A Shaabani S Samadi Z Badri and A Rahmati ldquoIonicliquid promoted efficient and rapid one-pot synthesis of pyranannulated heterocyclic systemsrdquo Catalysis Letters vol 104 no1-2 pp 39ndash43 2005
[22] G V Ramin T S Zahra andKN Rahman ldquoOne-pot synthesisof 4H-Chromene and Dihydropyrano[32-c]chromene deriva-tives in hydroalcoholicmediardquo Journal of the Brazilian ChemicalSociety vol 22 no 5 pp 905ndash909 2011
[23] H R Shaterian and A R Oveisi ldquoA simple Green approachto the synthesis of 2-amino-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile derivatives catalyzed by 3-hydroxypropanaminium acetate (HPAA) as a new ionicliquidrdquo Journal of the Iranian Chemical Society vol 8 no 2 pp545ndash552 2011
[24] H R Shaterian M Arman and F Rigi ldquoDomino Knoevenagelcondensation Michael addition and cyclization using ionicliquid 2-hydroxyethylammonium formate as a recoverablecatalystrdquo Journal of Molecular Liquids vol 158 no 2 pp 145ndash150 2011
[25] N Tavakoli-Hoseini M M Heravi F F Bamoharram andA Davoodnia ldquoGreen catalyst-free protocol for synthesis ofdihydropyrano[32-c] chromenes in ionic liquid [bmim]Br as anefficient promoting mediumrdquo Asian Journal of Chemistry vol23 no 8 pp 3599ndash3601 2011
[26] M G Dekamin M Eslami and A Maleki ldquoPotassiumphthalimide-N-oxyl a novel efficient and simple organocat-alyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in waterrdquo Tetrahedron vol 69no 3 pp 1074ndash1085 2013
[27] MHossein andKMMaryam ldquoCuOnanoparticles an efficientand recyclable nanocatalyst for the rapid and green synthesisof 34-dihydropyrano[c]chromenesrdquo Chinese Chemical Lettersvol 22 no 12 pp 1419ndash1422 2011
[28] H Yang R Tian and Y Li ldquoOrganic reactions catalyzed by 14-diazabicyclo [222] octane (DABCO)rdquo Frontiers of Chemistryin China vol 3 no 3 pp 279ndash287 2008
[29] B Baghernejad ldquo14-Diazabicyclo[222]octane (DABCO) asa useful catalyst in organic synthesisrdquo European Journal ofChemistry vol 1 no 1 pp 54ndash60 2010
[30] P Paliwal S R Jetti A Bhatewara et al ldquoDABCO catalyzedsynthesis of Xanthene derivatives in aqueous mediardquo ISRNOrganic Chemistry vol 2013 Article ID 526173 6 pages 2013
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
4 ISRN Organic Chemistry
Table 2 Synthesis of 2-Amino-4-aryl-3-cyano-5-oxo-4H5H-pyrano[32-c]chromenes in solvent-free neat conditions using DABCO(5mol) as catalyst
Entry Ar Product Timemin Yield mp∘C Found (reported)1 C6H5 4a 30 94 256-257 (256ndash258) [15]2 4-O2N C6H4 4b 30 96 259ndash261 (258ndash260) [15]3 3-O2N C6H4 4c 30 93 261ndash263 (262ndash264) [15]4 4-ClC6H4 4d 30 92 264ndash267 (263ndash265) [15]5 4-BrC6H4 4e 30 91 247ndash250 (249ndash251) [15]6 4-CH3OC6H4 4f 30 89 241ndash244 (240ndash242) [15]7 4-CH3C6H4 4g 30 87 252ndash254 (250ndash252) [15]8 24-Cl2C6H3 4h 30 90 256ndash258 (257ndash259) [15]
9
O
4i 30 97 251ndash254 (252-253) [16]
10
S
4j 30 96 226ndash230 (228) [20]
(400MHz DMSO-d6 120575ppm) 3194 5784 10397 11622
11894 12251 12427 12458 12467 12772 13252 1384114090 15295 15384 15840 15949
Acknowledgment
The authors thank the director of SAIF Punjab UniversityChandigarh for NMR spectral data
References
[1] A Domling ldquoRecent developments in isocyanide based multi-component reactions in applied chemistryrdquo Chemical Reviewsvol 106 no 1 pp 17ndash89 2006
[2] I Ugi ldquoMulticomponent reactions (MCR) Perspectives of mul-ticomponent reactions and their librariesrdquo Advanced SynthesisandCatalysis vol 339 no 1 pp 499ndash516 1997
[3] N K Terrett M Gardner D W Gordon R J Kobylecki andJ Steele ldquoCombinatorial synthesismdashthe design of compoundlibraries and their application to drug discoveryrdquo Tetrahedronvol 51 no 30 pp 8135ndash8173 1995
[4] A Domling and I Ugi ldquoMulticomponent reactions with iso-cyanidesrdquo Angewandte Chemie vol 39 no 18 pp 3168ndash32102000
[5] K Tanaka and F Toda ldquoSolvent-free organic synthesisrdquo Chem-ical Reviews vol 100 no 3 pp 1025ndash1074 2000
[6] F Shirini K Marjani and H T Nahzomi ldquoSilica triflateas an efficient catalyst for the solvent-free synthesis of 34-dihydropyrimidin-2(1H)-onesrdquo Arkivoc vol 2007 no 1 pp 51ndash57 2007
[7] GThirunarayanan and G Vanangamudi ldquoSynthesis of some 4-bromo-1-naphthyl chalcones using silica-sulfuric acid reagentunder solvent free conditionsrdquoArkivoc vol 2006 no 12 pp 58ndash64 2006
[8] G R Green J M Evans A K Vong A R Katritzky C WRees and E F Scriven ldquoPyrans and their benzo derivativessynthesisrdquo in Comprehensive Heterocyclic Chemistry II vol 5 p469 Pergamon Press Oxford UK 1995
[9] W O Foye Principi Di Chemico Frmaceutica Piccin PadovaItaly 1991
[10] C S Konkoy D B Fick S X Cai N C Lan and J F W KeanaldquoPCT international application WO0075123 (2000)rdquo ChemicalAbstracts vol 134 Article ID 29313a 2001
[11] A Burgard H Lang and U Gerlach ldquoAsymmetric synthesis of4-amino-34-dihydro-22-dimethyl-2H-1 benzopyransrdquo Tetra-hedron vol 55 no 24 pp 7555ndash7562 1999
[12] J M Evans C S Fake T C Hamilton R H Poyserand G A Showell ldquoSynthesis and antihypertensive activityof 67-disubstituted trans-4-amino-34-dihydro-22-dimethyl-2H-1-benzopyran-3-olsrdquo Journal ofMedicinal Chemistry vol 27no 9 pp 1127ndash1131 1984
[13] J M Evans C S Fake T C Hamilton R H Poyserand E A Watts ldquoSynthesis and antihypertensive activityof substituted trans-4-amino-34-dihydro-22-dimethyl-2H-l-benzopyran-3-olsrdquo Journal of Medicinal Chemistry vol 26 no11 pp 1582ndash1589 1983
[14] R M Shaker ldquoSynthesis and reactions of some new 4H-pyrano[32-c]benzopyran-5-one derivatives and their potentialbiological activitiesrdquo Pharmazie vol 51 no 3 pp 148ndash151 1996
[15] A S Mohammadi and S Balalaie ldquoNovel and efficient catalystsfor the one-pot synthesis of 34-dihydropyrano[c]chromenederivatives in aqueous mediardquo Tetrahedron Letters vol 48 pp3299ndash3303 2007
[16] M Kidwai and S Saxena ldquoConvenient preparation of pyranobenzopyranes in aqueous mediardquo Synthetic Communicationsvol 36 no 18 pp 2737ndash2742 2006
[17] J M Khurana and S Kumar ldquoTetrabutylammonium bromide(TBAB) a neutral and efficient catalyst for the synthesis ofbiscoumarin and 34-dihydropyrano[c]chromene derivatives in
ISRN Organic Chemistry 5
water and solvent-free conditionsrdquo Tetrahedron Letters vol 50no 28 pp 4125ndash4127 2009
[18] M Seifi and H Sheibani ldquoHigh surface area MgO as ahighly effective heterogeneous base catalyst for three-component synthesis of tetrahydrobenzopyran and 34-dihydropyrano[c]chromene derivatives in aqueous mediardquoCatalysis Letters vol 126 no 3-4 pp 275ndash279 2008
[19] M M Heravi B A Jani F Derikvand F F Bamoharramand H A Oskooie ldquoThree component one-pot synthesisof dihydropyrano[32-c]chromene derivatives in the presenceof H6P2W18O62sdot 18H
2O as a green and recyclable catalystrdquo
Catalysis Communications vol 10 no 3 pp 272ndash275 2008[20] H J Wang J Lu and Z H Zhang ldquoHighly efficient
three-component one-pot synthesis of dihydropyrano[32-c]chromene derivativesrdquo Monatshefte fur Chemie vol 141 no10 pp 1107ndash1112 2010
[21] A Shaabani S Samadi Z Badri and A Rahmati ldquoIonicliquid promoted efficient and rapid one-pot synthesis of pyranannulated heterocyclic systemsrdquo Catalysis Letters vol 104 no1-2 pp 39ndash43 2005
[22] G V Ramin T S Zahra andKN Rahman ldquoOne-pot synthesisof 4H-Chromene and Dihydropyrano[32-c]chromene deriva-tives in hydroalcoholicmediardquo Journal of the Brazilian ChemicalSociety vol 22 no 5 pp 905ndash909 2011
[23] H R Shaterian and A R Oveisi ldquoA simple Green approachto the synthesis of 2-amino-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile derivatives catalyzed by 3-hydroxypropanaminium acetate (HPAA) as a new ionicliquidrdquo Journal of the Iranian Chemical Society vol 8 no 2 pp545ndash552 2011
[24] H R Shaterian M Arman and F Rigi ldquoDomino Knoevenagelcondensation Michael addition and cyclization using ionicliquid 2-hydroxyethylammonium formate as a recoverablecatalystrdquo Journal of Molecular Liquids vol 158 no 2 pp 145ndash150 2011
[25] N Tavakoli-Hoseini M M Heravi F F Bamoharram andA Davoodnia ldquoGreen catalyst-free protocol for synthesis ofdihydropyrano[32-c] chromenes in ionic liquid [bmim]Br as anefficient promoting mediumrdquo Asian Journal of Chemistry vol23 no 8 pp 3599ndash3601 2011
[26] M G Dekamin M Eslami and A Maleki ldquoPotassiumphthalimide-N-oxyl a novel efficient and simple organocat-alyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in waterrdquo Tetrahedron vol 69no 3 pp 1074ndash1085 2013
[27] MHossein andKMMaryam ldquoCuOnanoparticles an efficientand recyclable nanocatalyst for the rapid and green synthesisof 34-dihydropyrano[c]chromenesrdquo Chinese Chemical Lettersvol 22 no 12 pp 1419ndash1422 2011
[28] H Yang R Tian and Y Li ldquoOrganic reactions catalyzed by 14-diazabicyclo [222] octane (DABCO)rdquo Frontiers of Chemistryin China vol 3 no 3 pp 279ndash287 2008
[29] B Baghernejad ldquo14-Diazabicyclo[222]octane (DABCO) asa useful catalyst in organic synthesisrdquo European Journal ofChemistry vol 1 no 1 pp 54ndash60 2010
[30] P Paliwal S R Jetti A Bhatewara et al ldquoDABCO catalyzedsynthesis of Xanthene derivatives in aqueous mediardquo ISRNOrganic Chemistry vol 2013 Article ID 526173 6 pages 2013
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
ISRN Organic Chemistry 5
water and solvent-free conditionsrdquo Tetrahedron Letters vol 50no 28 pp 4125ndash4127 2009
[18] M Seifi and H Sheibani ldquoHigh surface area MgO as ahighly effective heterogeneous base catalyst for three-component synthesis of tetrahydrobenzopyran and 34-dihydropyrano[c]chromene derivatives in aqueous mediardquoCatalysis Letters vol 126 no 3-4 pp 275ndash279 2008
[19] M M Heravi B A Jani F Derikvand F F Bamoharramand H A Oskooie ldquoThree component one-pot synthesisof dihydropyrano[32-c]chromene derivatives in the presenceof H6P2W18O62sdot 18H
2O as a green and recyclable catalystrdquo
Catalysis Communications vol 10 no 3 pp 272ndash275 2008[20] H J Wang J Lu and Z H Zhang ldquoHighly efficient
three-component one-pot synthesis of dihydropyrano[32-c]chromene derivativesrdquo Monatshefte fur Chemie vol 141 no10 pp 1107ndash1112 2010
[21] A Shaabani S Samadi Z Badri and A Rahmati ldquoIonicliquid promoted efficient and rapid one-pot synthesis of pyranannulated heterocyclic systemsrdquo Catalysis Letters vol 104 no1-2 pp 39ndash43 2005
[22] G V Ramin T S Zahra andKN Rahman ldquoOne-pot synthesisof 4H-Chromene and Dihydropyrano[32-c]chromene deriva-tives in hydroalcoholicmediardquo Journal of the Brazilian ChemicalSociety vol 22 no 5 pp 905ndash909 2011
[23] H R Shaterian and A R Oveisi ldquoA simple Green approachto the synthesis of 2-amino-5-oxo-45-dihydropyrano[32-c]chromene-3-carbonitrile derivatives catalyzed by 3-hydroxypropanaminium acetate (HPAA) as a new ionicliquidrdquo Journal of the Iranian Chemical Society vol 8 no 2 pp545ndash552 2011
[24] H R Shaterian M Arman and F Rigi ldquoDomino Knoevenagelcondensation Michael addition and cyclization using ionicliquid 2-hydroxyethylammonium formate as a recoverablecatalystrdquo Journal of Molecular Liquids vol 158 no 2 pp 145ndash150 2011
[25] N Tavakoli-Hoseini M M Heravi F F Bamoharram andA Davoodnia ldquoGreen catalyst-free protocol for synthesis ofdihydropyrano[32-c] chromenes in ionic liquid [bmim]Br as anefficient promoting mediumrdquo Asian Journal of Chemistry vol23 no 8 pp 3599ndash3601 2011
[26] M G Dekamin M Eslami and A Maleki ldquoPotassiumphthalimide-N-oxyl a novel efficient and simple organocat-alyst for the one-pot three-component synthesis of various 2-amino-4H-chromene derivatives in waterrdquo Tetrahedron vol 69no 3 pp 1074ndash1085 2013
[27] MHossein andKMMaryam ldquoCuOnanoparticles an efficientand recyclable nanocatalyst for the rapid and green synthesisof 34-dihydropyrano[c]chromenesrdquo Chinese Chemical Lettersvol 22 no 12 pp 1419ndash1422 2011
[28] H Yang R Tian and Y Li ldquoOrganic reactions catalyzed by 14-diazabicyclo [222] octane (DABCO)rdquo Frontiers of Chemistryin China vol 3 no 3 pp 279ndash287 2008
[29] B Baghernejad ldquo14-Diazabicyclo[222]octane (DABCO) asa useful catalyst in organic synthesisrdquo European Journal ofChemistry vol 1 no 1 pp 54ndash60 2010
[30] P Paliwal S R Jetti A Bhatewara et al ldquoDABCO catalyzedsynthesis of Xanthene derivatives in aqueous mediardquo ISRNOrganic Chemistry vol 2013 Article ID 526173 6 pages 2013
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
