Betty Weiss LAB :DA.docx

7/26/2019 Betty Weiss LAB :DA.docx

1/18

1

The Semi-Microscale Diels-Alder Reaction

of Anthracene with Maleic Acid

Instructor : Dilusha Harischandra ,PhD

Student: Betty Weiss


2/18

Lab S!T "#": The Diels $Alder Reaction of Anthracene with Maleic Anh%dride&

Semi-Microscale Diels $Alder Reaction

by : 'ett% (eiss

Date of experiment:

)ebruar% *+, *#

I!TR.D/0TI.!

In 1950 Otto Diels and Kurt Alder have been awarded the obel !ri"e for #hemistry$ %hey des&ribed a

very important rea&tion' whi&h is suitable for the formation of &arbon(&arbon bond in a six membered

rin) with hi)h stereo &hemi&al &ontrol$

Otto Diels Kurt Alder

1*+,(195- 190.(195*

Since 1928 several new compounds have been synthesized with the use of Diels-Alder (DA) reaction.

This reaction provides an easier way for cyclization than other ring closure procedures of open-chain

compounds.

.'120TI32

%he purpose of this experiment is to form 9' 10(dihydroanthra&ene(9'10(/' (su&&ini& anhydride by

2


3/18

way of a Diels Alder rea&tion between anthra&ene and malei& anhydride$ Anthra&ene a&ts as the diene

and malei& anhydride fun&tions as the dienophile$ ollowin) the rea&tion' the &rude produ&t will be

re&rystalli"ed$ 2eltin) points of both the &rude produ&t and re&rystalli"ed produ&t will be ta3en and

&ompared with the literature value$ Also' an infrared spe&trum of the re&rystalli"ed produ&t will be

ta3en$ 4oth meltin) points and the infrared spe&trum will be used to &hara&teri"e the produ&t$

0H2MI0AL R2A0TI.!

#1-

106 #

-

.O

7#

1*

1.O

7

M20HA!ISM

3


4/18

)i4ure #: Antra&ene 8s rin) rea&ts as a diene' the produ&t has two fully aromati& rin)s' ea&h with six pi

ele&trons$

MAT2RIALS

.50 ml bea3er

boilin) &hip

4u&hner funnel' with adapter

&ondenser with tubin)' ele&tri& flas3 heater' hot plate' support stand

50 ml rlenmeyer flas3

1.5 ml filter flas3 with va&uum tubin)' filter paper

10 ml )raduated &ylinder

.5 ml round bottom flas3

17x100 mm test tube

. meltin) point &apillary tubes

mi&ro spatula

wat&h )lass

7 ml produ&t vial

R2A52!TS A!D PR.P2RTI2S

#&

4


5/18

Anthracene +6 7

#1-10

22: 1+*$.7 );mol

2!: .1,(.1* < #

4!: 779$9 < #

a"ard: =nli3e many other poly&y&li& aromati& hydro&arbons >!A?' anthra&ene is not &lassified as

&ar&ino)eni& as listed by the =$@$ a)en&y O@A$ Anthra&ene' as many other !As' is )enerated durin)

&ombustion pro&esses: xposure to humans happens mainly throu)h toba&&o smo3e and in)estion of

food &ontaminated with &ombustion produ&ts$Irritant$

*&

Maleic Anh%dride

#-.O7

22: 9*$0, );mol

2!: 5-(5,


6/18

a"ard: %his &ompound also poses relatively low(ris3 environmental ha"ards' an important feature for

those appli&ations$ xposure to malei& anhydride may &ause respiratory tra&t' eye irritation' s3in

irritation and respiratory irritation$ 2alei& anhydride is a s3in and respiratory sensiti"er$ %oxi& and

&orrosive$

8&

Potassium 'romide

K4r

a"ard: !otassium bromide K4r is a salt widely used as an antiepilepti& dru)s and a sedative in the

late 19th and early .0th &enturies' with over(the(&ounter use extendin) to 19+5 in the =@$ Its a&tion is

due to the bromide ion' K4r is eBually effe&tive$ !otassium bromide is used as a veterinary dru)' as an

antiepilepti& medi&ation for do)s$

=nder standard &onditions' potassium bromide is a white &rystalline powder$ It is freely soluble in

water$ In a dilute aBueous solution' potassium bromide tastes sweet' at hi)her &on&entrations it tastes

bitter' and tastes salty when the &on&entration is even hi)her$ %hese effe&ts are mainly due to the

6


7/18

properties of the potassium ionCsodium bromide tastes salty at any &on&entration$ In hi)h

&on&entration' potassium bromide stron)ly irritates the )astri& mu&ous membrane' &ausin) nausea and

sometimes vomitin)$ Irritant and hydros&opi&$

9&

%lene ;#,* $dimeth%lben


8/18

>&

9'10(dihydroanthra&ene(

+,#-?,@-succinic anh%dride

;roduct=

#1*1.O7

22: .+,$.9);mol

2!: .,.(.,- < #

a"ard: armfulifswallowed' &auses s3in' eye irritation and respiratory irritation$

PR.02D/R2

Part # Hea&tin) Anthra&ene with 2alei& Anhydride%are a .5(m roundbottom flas3 and re&ord the

mass$ Jei)h 0$5 ) of anthra&ene and 0$.5) of malei& anhydride and pla&e them in the .5 ml round

bottom flas3$ Add ,$0 m of xylene and a boilin) &hip$ it the vial or tube with a &ondenser' as shown

in i)ure . on #hemistry ab xperiments @% +1+$ %urn on the water to the &ondenser and heat the

mixture ' use a .00


9/18

produ&t and set aside a small sample to dry$ %his sample will later be used to measure the meltin) point

of the &rude produ&t$

)i4ure *: RefluBin4 aaratus with condenser

)i4ure 8: 'Cchner flas with funnel

Part * !urifyin) the !rodu&t%o perform re&rystalli"ationL pla&e the produ&t in a 50(m rlenmeyer

flas3$ Add 5(10 m of xylene and heat the mixture )ently in a sand bath until the xylene boils$

9


10/18

Mradually add more xylene until the entire produ&t dissolves or until no more appears to be dissolvin)$

4e sure not to ex&eed 15 m of total volume xylene$ If solid impurities are still present' use a !asteur

pipet to transfer the solution to another 10(m rlenmeyer flas3$ Allow the solution to &ool to room

temperature and then &ool the solution in an i&e bath for 5 minutes$ If its ne&essary' s&rat&h the bottom

of the flas3 with a )lass rod to indu&e &rystalli"ation$ #olle&t the &rystalli"ed solid by va&uum

filtration' usin) a 4u&hner funnel and rinse the &rystals with 7 m of i&e(&old xylene$ @pread the

produ&t &rystals thinly over a &lean wat&h )lass and allow them to dry for approximately 70 minutes$

%hen wei)h the produ&t and re&ord the mass' than pla&e the produ&t in a labeled vial$

Part 8 #hara&teri"in) the !rodu&t2easure the meltin) points for both the &rude produ&t and the

re&rystalli"ed produ&t$ !erform an infrared spe&trum on both produ&ts$ Add 100 m) K4H to

approximately 1 m) of the produ&t$ 2ix the two usin) a mortar and pestle' bein) sure to )rind the two

&ompounds into a fine powder$ !la&e some of this mixture in a mi&ro&up' ma3in) sure the surfa&e is

smooth$ %hen pla&e the pellet in the infrared spe&trometer and obtain an infrared spe&trum of the

produ&t$ #ompare the produ&t spe&trum with the spe&tra of malei& anhydride and anthra&ene in order

to &hara&teri"e the produ&t$

Part 9 #lean(uppla&e'all materials in their appropriate waste &ontainers' and wash your )lassware

with a soap deter)ent$

R2S/LTS A!D 0.!0L/SI.!S

mpty .5 ml round(bottom flas3: .,$0*7)

Antra&ene : 0$55.1 )

2alei& anhydride: 0$.,*. )

Jei)ht of the #rude produ&t: 1$.*7- )

Jei)ht of empty wat&h )lass: 5+$750* )

10


11/18

Jei)ht of wat&h )lass and produ&t: 5+$,50+)

)inal wei4ht of +,#-?,@-succinic acid anh%dride : &*+++ 4

Aearance: white, sli4htl% 4ra% in color, bri4ht cr%stals

0rude Meltin4 Point: *>>-*9&9 E0

Measured Meltin4 Point: **-*> E 0

11


12/18

Theoretical %ield of the roduct &"" 4

Wave number (cm-1) and Transmittance (T%)

12


13/18

)i4ure 9: Disla%in4 IR sectrum of the roduct&

R2)2R2!02S

http:;;www$physi&spost$&om;s&ien&e(arti&le(+-$htlm

13

3083 87

2985 84

2926 85

1863 39

1782 8

1643 74

1443 77

1416 67

1226 44

1069 36

1010 35

913 25

828 88

722 67

662 67

568 82
http://www.physicspost.com/science-article-74.htlmhttp://www.physicspost.com/science-article-74.htlm


14/18

P.ST-LA'.RAT.R F/2STI.! : S!T "#" ;'2TT (2ISS=

#& %he per&ent yield for the &rude produ&t was ++$05 N$ %he per&ent yield for the re&rystalli"ed produ&t

was -+$-.N$

*&%he per&ent re&overy from re&rystalli"ation was 5-$.1N$

The Diels-Alder Reaction of Anthracene with Maleic Anh%dride

8& ydrolysis of the !rodu&t: %he &arbons' whi&h are atta&hed to the oxy)en mole&ules by a double

bond' &arry a sli)htly positive &har)e$ @in&e oxy)en is more ele&trone)ative than &arbon' it pulls the

ele&trons towards it and &arbon is left with a sli)ht positive &har)e$ A water mole&ule with a lone pair

of ele&trons on the oxy)en atta&3s the sli)htly positive &arbon atoms$ %he water atta&hes' and then

loses a proton in order to stabili"e the positive &har)e$ %hus' two hydroxide )roups are added to the

mole&ule$ %he me&hanism of the rea&tion and the produ&t of this hydrolysis rea&tion are both shown

above$

14


15/18

9& He&rystalli"in) an anhydride su&h as the produ&t from this experiment from water or from an

al&ohol is rarely a )ood idea$ %his is be&ause anhydrides rea&t with water in the air and form a new

produ&t$ Jhen water or al&ohol is around' the lone pair of ele&trons on the oxy)en rea&t with the

produ&t and the produ&t under)oes a hydrolysis rea&tion to form a different produ&t' as shown above in

Buestion 7$ %hus' the re&rystalli"ed produ&t would not be the same produ&t obtained in the Diels Alder

rea&tion between anthra&ene and malei& anhydride$ %he produ&t >9' 10( dihydroanthra&ene(9'10(/' (

su&&ini& anhydride? in the rea&tion that was performed in this experiment rea&ts slowly and is easily

isolated and &hara&teri"ed before hydrolysis &an o&&ur$

>& ;a=%he &arbonyl re)ion of the produ&t IH spe&trum yielded pea3s at 1*,7 &m(1 and 1+*. &m(1$ On

the malei& anhydride spe&trum' the &arbonyl pea3s were lo&ated at 1*50 &m(1

and 1++* &m(1

$ %hese

are relatively &lose' and indi&ate that both the produ&t and the malei& anhydride have &arbonyl )roups

that to)ether have aldehyde fun&tionality$

>& ;b=es' the produ&t IH spe&trum allows me to &onfirm that the stru&ture of the produ&t is a

&ombination of the rea&tants anthra&ene and malei& anhydride$ %he produ&t spe&trum yields pea3s at

70*7 &m(1

and .9*5 &m(1

$ %hese indi&ated the presen&e of two ben"ene rin)s' and were &omparable to

pea3s at 7055 &m(1

' .9** &m(1

' and 7009 &m(1

on the anthra&ene spe&trum$ %he produ&t IH spe&trum

also &ontained pea3s at 1*,7 &m(1

and 1+*. &m(1

$ %hese pea3s indi&ated the presen&e of &arbonyl

)roups' and were &omparable to pea3s lo&ated at 1*5,'1*-* &m(1

and 1+*7 &m(1

on the malei&

anhydride spe&trum$ 4e&ause the produ&t spe&trum shares similarities with both the malei& anhydride

spe&trum and the anthra&ene spe&trum' it &an be &on&luded that the produ&t is a &ombination of the two

rea&tants$

15


16/18

)i4ure >: Disla%in4 sectrum of anthracene

16


17/18

)i4ure : Disla%in4 sectrum of maleic anh%dride

17


18/18

)i4ure ": Disla%in4 !MR sectrum of +,#- dih%droanthracene- +,# $?,@-succinic anh%dride

18

Betty Weiss LAB :DA.docx

Documents

Transcript of Betty Weiss LAB :DA.docx