* GB785348 (A)

Description: GB785348 (A)

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

PATENT SPECIFICATION 785,348 Date of Application and filing Complete Specification July 12, 1955. l if | No20141/55. Application made in Germany on July 12, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Class 1 ( 2), E 4 (AI: X). International Classification: -C Olb. COMPLETE SPECIFICATION Process for the Production of Metal Aluminium Hydrides or Aluminium Hydride We, FARBENFABRIKEN BAYER AXTIENGESELLSCHAFT, of Leverkusen-Bayerwerk, Germany, a Body Corporate, organised under the Laws of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:The present invention relates to a process for the production of metal aluminium hydrides, i e hydrides of aluminium and a metal other than aluminium, or aluminium hydride. By reacting solutions of aluminium halides, for example ethereal solutions of aluminium chloride or bromide, with metal hydrides, for example calcium or magnesium hydride, it is possible to produce soluble metal aluminium hydrides or aluminium hydride.

This process has the disadvantage that it involves the use of metal hydrides which, as produced by all the known processes, are obtained in a fused or highly sintered condition and do not react easily in non-aqueous media. The present invention is concerned with a process for the production of metal aluminium hydrides or aluminium hydride by reacting a metal hydride with an aluminium halide, wherein a finely divided mixture of a metal hydride with a metal which does not react with hydrogen to form a stable hydride is reacted with an aluminium halide. The mixture to be reacted with the aluminium halide may for example be produced by the process described and claimed in our copending Application No 19853/55 (Serial No 777,096) by the action of hydrogen on an alloy of a hydride forming metal and a metal which does not react with hydrogen to form a stable hydride, said alloy being in a finely divided form and substantially free from other elements. lPrice 3 s 6 d l Examples of metals which do not react with hydrogen to form stable hydrides are copper and aluminium During the above mentioned reaction, it is only the metal hydrides, for example Ca H, or Mg H,, which react, while the metals with which they are diluted, i e the metals which do not react with hydrogen to form stable hydrides, remain unaffected. Hitherto the most highly reactive magnesium hydride which could be prepared from magnesium and hydrogen gives a substantial yield, when reacted with aluminium chloride, only after a reaction lasting a number of days The reaction of aluminium chloride with a mixture of magnesium hydride and aluminium takes place practically quantitatively, in a few hours without the use of special stirring, comminuting or other means. The metal aluminium hydride or aluminium hydride which is formed is separated by filtration; the mixture of unchanged metal and of the salt formed can easily be separated by melting or dissolving. Mixtures of metal hydrides and metals, such as copper and calcium hydride, can for example be prepared by mechanically mixing a metal hydride with a metal. The following examole further illustrates the invention EXAMPLE gm of a mixture of about 32 % by weight of magnesium hydride and 68 % by weight of aluminium are boiled for four hours under reflux with 600 cc of ether and the stoichiometric amount of pure aluminium chloride either for the production of A 1 HY in accordance with the equation:2 A Cl, + 3 Mg H, + Al-+ 2 Al H, + 3 Mg Cl + Al or for the production of Mg(Al H,) in accordance with the equation:2 AI Cl, + 4 Mg H + AlMg(Al H 1)2 + 3 Mg Cl l + Al After cooling, the ethereal solution of 785,348 aluminium hydride or magnesium aluminium hydride is filtered off The residue is extracted with ether The yield of soluble hydrides is

practically quantitative Provided that pure aluminium chloride has been used, the residue consists of pure magnesium chloride mixed with aluminium powder.

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* GB785349 (A)

Description: GB785349 (A) ? 1957-10-23

Improvements in or relating to mechanical manipulators

Description of GB785349 (A)

PATENT SPECIFICATION 785,349 Date of Application and filing Complete Specification July 15, 1955. No 20558/55. Application made in United States of America on Dec 10, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Classes 73 ( 3), H( 13: 15); 78 ( 4), MX; and 83 ( 4), H 7 B. International Classification: -B 23 k B 66 f. COMPLETE SPECIFICATION Improvements in or relating to Mechanical Manipulators We, KROPP FORGE COMPANY, a Corporation organised and existing under the laws of the State of Illinois, United States of America, of 5301, West Roosevelt Road, Chicago, 50, Illinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to a mechanical manipulator for the handling of, for example, heavy or cumbersome articles which must be transported or moved from one place to another or from one work station to another in

a plant wherein work is to be done on the articles at various work stations. Although the manipulator according to the invention may be used in a number of applications it has been found to be particularly useful in the metal working industries, where a work-piece is transported, for example, from a furnace to a forge or similar metal working station As will be appreciated, in the usual metal working plant it is necessary to maintain a reasonable amount of working space between the various furnaces and the various metal working stations at which forging, punching, and other operations are carried out. In addition, workpieces which are being treated at a forging station, for example, require to be manipulated by rolling over or otherwise moving the work-piece after so many blows by the hammer. In large size metal working shops, the workpieces are of substantial size and weight and the problem of transporting such pieces from one station to another is greatly complicated by the cumbersome and heavy character of such pieces, and the entire operation is further complicated by the necessity for moving or rotating such pieces during a given forging operation Heretofore permanent tracks have been installed at great expense so that carriages movable thereon may be equipped with clamps, hoists and the like for carrying out the necessary manipulation of the articles Overhead hoists or similar lifting devices mounted lPrice on overhead tracks have also been used. Because of the weight of the articles involved, 50 the structures heretofore used have been more or less permanent in character thus limiting greatly the flexibility of the overall operation in moving pieces from one work station to another, while the ordinary track-mounted 55 hoist device is not adapted to carry out the great number of the movements required in manipulating certain pieces, particularly during complicated forging operations where it is necessary to reach into the furnaces, and 60 because of this it is necessary to employ a number of employees using levers and similar relatively crude devices The work by these employees involves numerous safety hazards, since they must be near the work-piece at the 65 work stations such as for example presses and forges. The aim of the present invention is to provide a mechanical manipulator which removes at least some of these disadvantages 70 According to the invention, the mechanical manipulator is designed for mounting on a truck and comprises a telescopic mast which supports a carriage arranged for up and down movement, a turntable rotatably mounted on 75 the carriage, and a pair of outwardly-extending arms which are each mounted at one of their ends on the turntable so as to be rotatable therewith, at least one of the arms being pivotally mounted on the turntable so that it can be 80 swung by driving means

towards and away from the other, in which the arms are of substantial length so that they can handle articles at an appreciable distance from the turntable, and are provided at their outer free ends with 85 hands having allochiral palms which, when the hands are in the closed position, define a space of generally polygonal cross-section between them. Two examples of mechanical manipulators 90 in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side elevation of a truck provided with a mechanical manipulator accord 95 ing to the invention; 785,349 Figure 2 is a side elevation of the arms and rotatable carriage assembly of the manipulator of Figure 1 and drawn to an enlarged scale; Figure 3 is a top plan view of the construction shown in Figure 2; Figure 4 is a section taken along the line IV-IV of Figure 3 and drawn to a further enlarged scale; Figure 5 is a section taken along the line V-V of Figure 2 and also drawn to a further enlarged scale; Figure 6 is a view similar to Figure 5, but showing an alternative construction of manipulator according to the invention; Figure 7 is a top plan view of the alternative construction shown in Figure 6; and Figure 8 is a side elevation of the construction of Figures 6 and 7. Figure 1 of the drawings shows a truck 10, provided with drive wheels 11 driven from either an internal combustion motor or an electric motor (not shown) positioned within a hood 13 positioned at the rear of the truck 10 for weight balance of the truck with rear steering wheels 12 operatively connected to a manually operated steering wheel 14, and with a control panel 15 mounted near the steering wheel 14. A telescopic mast 16 is mounted on the front end of the truck 10, for swinging about pivots P on opposite sides of the truck, by means of side plates 17 secured as by welding to the bottom of the mast 16 A double action piston and cylinder 18 supported on the truck and connected by a pivot 19 to the rear of mast 16 centrally thereof is actuated by a lever 20 on the control panel 15, which actuates a magnetic contactor in the circuit of an electric motor driving a pump connected to the hydraulic cylinder 18, to operate the hydraulic cylinder or drive means 18 so as to effect tilting of the mast 16 about the pivots P in known manner. This tilting movement of the mast 16 effects limited arcuate or swinging movement of the mast 16 so that parts carried thereby (which will be described hereinafter) and extending generally normal to the mast 16 can be swung from a position extending downwardly towards the ground G to a position extending upwardly a limited number of degrees (i e about 20 to ) from the horizontal. The telescopic mast 16 is a conventional structure as employed in

industrial lift trucks and comprises side channel members 16 a, a slide member 16 b carried between the channel members 16 a for guided vertical movement, a looped lifting chain 16 c anchored to the top of the slide 16 b and looped over a pulley 16 d and anchored at 16 e to the side channels 16 a, and a hydraulic piston and cylinder 16 f anchored to a top frame member 16 g and operatively connected to the pulley 16 d for movement vertically up and down to lift the slide 16 b The positioning of the various elements within the mast 16 is shown in diagrammatic and simplified form which in actual practice is altered so as effectively to permit movement of the slide 16 b substantially the full length of the channel members 16 a. The slide 16 b has secured thereto by bolts 70 (not shown) a rectangular supporting frame 21 positioned on the forward face thereof and extending across the side channel members 16 or, the frame 21 being thus tiltable with the hoist assembly 16 Carried by the frame 21 are 75 a turntable 22 rotatably mounted on the frame 21, driving means 23 in the form of an hydraulic motor for rotating the turntable 22, and a pair of arms 24 a and 24 b pivotally carried at their base ends 25 a and 25 b by a carriage 80 26 attached to the turntable 22 A pair of hands 27 a and 27 b are carried at the outer extremities of the arms 24 a and 24 b, respectively, and a further driving means 28, in the form of a hydraulic piston and cylinder, are 85 provided on the carriage 26 for selectively swinging the arms 24 a and 24 b away from and toward each other to release and to grasp articles (not shown) by the hands 27 a and 27 b 90 Referring now to Figures 3, 4 and 5, it will be seen that the turntable 22 is a generally circular member rotatably mounted on a fixed axle member 29 (Figures 1 and 2) secured to the frame 21 95 The turntable 22 comprises a front, generally annular plate 22 a and a rear plate 22 b having gear teeth 22 c at the outer periphery thereof The gear teeth 22 c are engaged by a pinion gear 30 operatively engaged by a 100 worm gear 31 driven by the hydraulic motor 23 The hydraulic motor 23 is connected to a hydraulic pump circuit (not shown) controlled through the control panel 15 for selectively driving the hydraulic motor 23 forwardly or 105 in reverse so as to rotate the turntable 22 through 360 ' in either direction by means of the pinion gear 30 A pair of rollers 32 and 33 (Figure 5) rotatably carried by supports 34 and 35, respectively, secured to the frame 21 110 rotatably engage the top outer side of the front plate 22 a of the turntable 22, to resist outward tilting of the turntable 22 at the top thereof. Bottom rollers 36 and 37 rotatably carried by supports 38 and 39, respectively secured to 115 the frame 21, engage the bottom of the rear face of the rear plate 22 b of the turntable 22 for the purpose of preventing tilting of the bottom portion of the turntable 22

towards the frame 21 120 The carreige 26 comprises a housing of generally rectangular cross-section and having vertically extending side walls 26 P and 26 b secured to outwardly extending angle irons 40 welded at their base ends to the turntable 22, 125 and removable top and bottom walls 26 c and 26 d, respectively, secured by bolts (not shown) to the irons 40 (Figure 5) The axle member 29 is positioned to extend axially of the turntable 22 and the carriage 26 is centrally positioned 130 785,349 on the turntable 22 so as to extend axially outwardly therefrom. Pivot pins, in the form of heavy bolts 41 a and 41 b are received through apertures in the carriage bottom wall 26 d and extend upwardly through apertures in the carriage top wall 26 c to be secured i; position by nuts 42 a and 42 b. The pivot pins 41 a and 41 b extend through apertures in the arm base portions 25 a and 25 b, and carry lower spacers 43 a and 43 b and upper spacers 44 a and 44 b which fix the relative horizontal position of the base end portions 25 a and 25 b in the carriage 26. As will be seen most clearly from Figure 3, the arm base portions 25 a and 25 b are pivotally mounted on the pins 41 a and 41 b near the extreme ends or shoulder portions 45 a and b of the arms, which shoulder portions are flared or turned outwardly behind the side walls 26 a and 26 b and between the angle irons 40, and are then swept backwardly towards pivot pin mountings 46 a and 46 b at each end. The drive means 28 for swinging the arms 24 a and 24 b comprises a hydraulic cylinder 28 a connected to fluid pressure lines in an actuating fluid pressure system (not shown) and having at one end a piston rod 28 b' connected to the pivot pin 46 a the opposite end of the cylinder 28 a being pivotally anchored to the pivot pin 46 b, so that in order to open the arms 24 a and 24 b the piston rod 28 b is drawn into the cylinder 28 a to pull the pivot pins 46 a and 46 b together, as shown in the broken line in Figure 3. The arm end portion 25 a is provided with pivot pins 47 a and 48 a positioned on opposite sides of the main pivot 41 a, and pivot pins 47 b and 48 b are suitably mounted in the arm end portion 25 b on opposite sides of the main pivot 41 b in a similar manner A linking bar interconnects the pin 47 a with the pin 48 b and a linking bar 49 interconnects the pivot pins 47 b and 48 a, the linking bars 49 and 50 cooperating with the " floating " drive means 28 carried by the arm extremities 45 a and 45 b so that the arms 24 a and 24 b will move inwardly and outwardly through substantially the same number of degrees upon driving movement of the drive means 28. The arm base ends 25 a and 25 b are heavy frame members (preferably of steel or similar high strength material) which extend outwardly from the carriage 26 a short distance and have secured thereto the arms

proper 24 a and 24 b As shown in Figures 4 and 5, the arm portions 24 a and 24 b are of substantially square cross section, and are seated in opposed V-shaped grooves 5 la and 5 lb extending longitudinally of the outer end portions of the arm base ends 25 a and 25 b, respectively, the arms being retained in the grooves 51 a and 51 b by a number of bolts 52 The arms 24 a and 24 b are of substantial length so that they can handle articles at an appreciable distance from the turntable 22, and for purposes of strength are engaged in the V-shaped grooves 5 la and Sib, so that the diagonals of the square crosssection extend respectively vertically and horizontally As shown in Figures 3 and 4, the 70 outer extremities or wrist portions of the arms 24 a and 24 b are twisted as at 52 a and 52 bs respectively, to give the required initial formation of the hands 27 a and 27 b The wrist portions 52 a and 52 b are formed in this manner 75 so that the opposed fiat sides S thereof may be brought closely together and the hands are then twisted outwardly as at 53 a and 53 b generally normal to the wrist portions 52 a and 52 b, through a downward portion 54 a and 54 b 80 (also generally normal to the plane of the arms 24 a and 24 b, and then turned inwardly to provide a pair of hand portions 55 a and 55 b slightly pointed at their inward extremities to facilitate grasping the articles As will be seen 85 in Figure 4, the hand portions 53 a, 54 a and a, and 53 b, 54 b and 55 b present opposed cupped surfaces of allochinal palms 56 a and 56 b, respectively which serve generally to define therebetween a space of generally poly 90 gonal cross-section As shown in Figure 4, the cross-sectional area of the space between the hands 27 a and 27 b is approximately a rectangle defined by generally horizontal top and bottom walls ( 53 a, 53 b and 55 c and 55 b) and 95 by generally vertical side walls ( 54 a and 54 b), so that it is possible to provide wall portions which grasp an article so as to provide supporting force components for substantially the entire periphery of the cross-section ot the 100 article, (as here indicated by the cross-section of the space) between the hands, and the article will be properly supported during the entire rotary movement of the turntable 22 through 360 , the axis of rotation of the turntable being 105 shown at a in Figure 4 The arms 24 a and 24 b (with the integral hands 27 c and 27 b) swing towards and away from each other in a plane P-P generally passing through the turntable axis a and the central axis of the polygonal 110 space between the palms 56 a and 56 b passes through a point al and is generally parallel to but spaced from the turntable axis a This " off set " feature of the hands 27 c and 27 b is found to be advantageous in certain circumstances for 115 rotary manipulation of articles in a forge, for example. Referring now to Figures 6, 7 and 8, which show somewhat different arm and carriage mountings, there is provided a turntable 122 120 having a

structure generally similar to that of the turntable 22, and including a front face portion 122 c and a rear gear portion 122 b operatively engaging a pinion gear 130 driven by suitable drive means (not shown) in sub 125 stantially the same manner in which the drive means 23, pinion gear 30 and turntable 22 co,. operate Top rollers 132 and 133 engage the outer face of the turntable 122 and bottom rollers 136 and 137 engage the inner face of 130 785,349 the turntable 122 The various elements in Figures 6, 7 and 8 having functions substantially identical to corresponding elements in the previously described Figures 2 to 5 are indicated by reference numerals which are increased by one hundred An axle member 129 rotatably supports the turntable 122 and is secured to a supporting frame 121 which is secured to the hoist assembly and actuating fluid for a drive mechanism 128 positioned within a carriage indicated generally at 126 and carried by the turntable 122, is supplied through suitable control means (not shown) and supply lines coaxially received within the axle portion 129 and indicated generally at in Figure 8. The carriage 126 is of generally rectangular cross-section and is secured to the central portion of the turntable 122 so as to extend generally axially outwardly therefrom; the said carriage 126 comprising side walls 126 a and 126 b secured as by welding to the front face 122 W of the turntable 122, and top and bottom walls 126 c and 126 d, respectively, suitably secured as by bolts to the side walls 126 and 126 b In the embodiments of Figures 6, 7 and 8, the tongs or arms proper 124 W and 124 b are substantially identical to the arms 24 a and 24 b with associated hands 27 W and 27 b, and the extended hand portions of the arms 124 a and 124 b are therefore not shown It will be noted, however, that one of the arms, namely the arm 124 a is held against movement while the arm 124 b is pivotally mounted, in a manner hereinafter to be described A supporting framework 61 having the general shape of an angle iron extends outwardly from the front or outer end of the carriage 126 and is secured thereto as by welding The supporting framework 61 has mounted within the V-shaped portion of its angle iron structure a supporting block 62 (Figure 6) which cooperates with the framework 61 to define a V-shaped groove 63 which receives and securely retains one end of the arm 124 W by means of bolts 64 in substantially the same manner in which the arm 24 a is retained in the base portion 25 a of the construction of Figures 2 to 5. A protruding framework 65 of similar shape to the framework 61 carries a loading block 66 which defines therewith a V-shaped notch 67 receiving and securely mounting the end of the arm 124 b by means of bolts 68 The framework 65, is, however, movable and is carried by a pivot arm 69 The pivot arm 69 has a generally U-shaped bracket 70

secured thereto by means of bolts 71 and the legs 70 a of the bracket 70 extend outwardly to embrace a rectangularly cross-sectional back portion 65 w of the framework 65 A pivot pin 72 carried by the U-shaped bracket 70 pivotally supports the framework 65 for limited amount of pivotal movement sufficient to obtain alignment between the arms 124 a and 124 b when a load is applied thereto for the purpose of picking up an article As will be seen in Figure 7, the outer edge of the pivot arm 69 limits the pivotal movement of the framework 65 and a guide member 73 carried by the framework 65 presents a cam surface to a mating guide mem 7 ber 74 carried on the framework 61 to further limit pivotal movement of the framework 65 and also to assist in aligning the framework with the stationary framework 61 The pivot arm 69 is pivotally mounted on a pivot 7 ' pin 75 carried by the carriage 126 and passing through the top and bottom walls 126 c and 126 d thereof respectively thereby to provide relative swinging movement between the arms 124 W and 124 b Conveniently a limited sliding 8 ( movement of the pivot 75 or sliding adjustment of the said pivot may be provided The end 69 a of the pivot arm opposite to the end carrying the framework 65, is connected by a pivot 77 to a drive means indicated generally at 8 ' 128 The drive means 128 comprises a pair of superposed double acting hydraulic piston and cylinder units as shown in Figure 8, the piston rods 128 b of which are connected to the pivot arm end 69 W by a pair of pivots 77 and 9 W the cylinders 128 W of which are anchored by means of pivot pins 78 to the side wall 126 a of the carriage 126 On the opposite carriage side wall 126 b there is mounted a motion limiting block 79 which extends at one end as 9 ' at 79 W outwardly beyond the pivot 75 so as to limit the outward swinging movement of the pivot arm 69 and which also presents a rear surface 79 b which prevents inward swinging movement of the pivot arm 69 beyond a cer 10 tain desired point A control valve member 179 connected to the fluid pressure supply lines 60 provides communication with high pressure lines 80 connected at opposite ends of the actuating cylinders 128 a to supply the necessary 10 actuating fluid pressure thereto In the construction of Figures 6, 7 and 8, the combination of the fixed arm 124 W and a single movable arm 124 b can provide greater gripping strength between the arms than that which 11 may be obtained with the construction of Figures 2 to 5, since all the actuating force is applied to a single arm 124 b and additional strength can be employed in holding the arm 124 a Also the grasping of articles of any bulk 11 can usually be more conveniently handled by the arms 124 W and 124 b, although the movement of both arms 24 W and 24 b of Figures 2 to 5 does provide for a much wider opening between the hands 27 a and 27 b, if such is 12 desired Also, the application of the driving force in a substantially uniform manner to the two arms 24 W and 24 b as

well as the coordinated movement between these two arms offers a number of advantages over the arms 124 a 12 and 124 b in the proper handling or articles.

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* GB785350 (A)

Description: GB785350 (A) ? 1957-10-23

Method of separating nickel and cobalt

Description of GB785350 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

BE539910 (A) CH328069 (A) DE1041024 (B) FR1134804 (A) US2793936 (A) BE539910 (A) CH328069 (A) DE1041024 (B) FR1134804 (A) US2793936 (A) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

P ATENT SPECEFICATION 780 4 Date of Application and filing Complete Specification July 19, 1955.

No 20901/55. Application made in Switzerland on July 19, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance: -Class 1 ( 3), AI(D 10: G 22 D 1 O: N 9). International Classification: -C Olg. COMPLETE SPECIFICATION Method of Separating Nickel and Cobalt We, LONZA ELECTRIC AND CHEMICAL Wo R Ks LTD, of 72, Aeschenvorstadt, Basle, Switzerland, a Body Corporate organised under the Laws of Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a method of separating nickel and cobalt from a mixture of divalent and trivalent mixed hydroxides thereof. Mixtures of divalent and trivalent nickel and cobalt hydroxides are obtained for example in the metallurgical processing of raw ore using dry, wet or electrochemical methods. None of the known processes has been able to achieve satisfactory separation of the nickel hydroxides from the cobalt hydroxides, particularly in cases where the ratio of nickel to cobalt in the mixed hydroxide varied. The present invention consists in a method of separtaing nickel and cobalt from a mixture of nickel and cobalt hydroxides at least a portion of which are in divalent form, which comprises oxidising the mixture in an aqueous medium so as to form a mixture of trivalent nickel hydroxide and trivalent cobalt hydroxide and submitting the resulting mixture of trivalent nickel and cobalt hydroxides to an extraction treatment with an aqueous chlorine-containing liquor in an amount sufficient to cause dissolution of substantially all the nickel hydroxide but to leave the trivalent cobalt hydroxide undissolved, thereby separating the nickel from the cobalt hydroxide. Due to the fact that mixtures of nickel and cobalt hydroxides which are obtained in industry from metallurgical treatments are almost always in the form of mixtures of divalent and trivalent nickel and cobalt hydroxides, it is necessary first to oxidise such mixtures so as to convert all of the hydroxides to the trivalent form before the extraction step in order to prevent the loss of any of the nickel or cobalt. The amount of the aqueous medium with reference to the amount of the mixed hydroxides should be such that a slurry or pasty mixture is formed The oxidation is preferably carried out by means of a chlorinecontaining solution or a solution which gives up chlorine, e g by an aqueous solution containing chlorine, a soluble chlorate or hypochlorite By the oxidation of the mixed hydroxides in the form of a

slurry, that is, in the presence of a small amount of liquid, for example between 10 and 60 %, and preferably between 30 and 40 %, of water based on the amount of the mixed hydroxides, so that the mixture of the water and the mixed hydroxides is in the form of a slurry or a foam, loss of substance by dissolution is -greatly avoided. In addition to the above-mentioned oxidation agents, such as chlorine, chlorates and hypochlorites, any other suitable oxidation agent may be utilised provided no undesirable residue from the oxidation remains The oxidaiton is preferably carried out at room temperature, although higher temperature, suitably 45-50 C, may be utilised within practical limits; for example, when an aqueous solution of chlorine is utilised as the oxidising agent a temperature of 100 C should not be exceeded in order to prevent the loss of excessive amounts of chlorine. After oxidation in a liquid medium in which the hydroxides form a slurry, the oxidised hydroxides, e g trivalent nickel and cobalt hydroxides, are separated from the liquid medium by filtration or, preferably, centrifuging The mixture of trivalent nickel and cobalt hydroxides are then submitted to extraction by means of a large amount of a chlorine-containing aqueous solution, whereby substantially all of the trivalent nickel hydroxide goes into solution while substantially all of the trivalent cobalt hydroxide remains undissolved The nickel hydroxide and the cobalt hydroxide may then be revovered separately by any suitable means. The extracting agent must be an aqueous solution of chlorine: Although the other halogens can be used instead of chlorine, they are so expensive as to be industrially impractical and 5,350 785,350 are not included within the scope of the present invention The aqueous solution is preferably saturated with chlorine and, in order to increase the amount of chlorine which the solution may contain and thereby to increase the dissolving ability for trivalent nickel hydroxide of the solution, the aqueous solution should also contain a carrier salt which has the property of permitting the aqueous solution to hold more chlorine and simultaneously aid in the extraction of the trivalent nickel hydroxide. Such carrier salt is preferably the chloride of a metal the hydroxide of which is water soluble For example, sodium chloride, calcium chloride are suitable for this purpose. Sodium chloride is, of course, most preferred for reasons of ready availability and economy. The aqueous extracting solution preferably 0 contains between 50 and 500 gin per litre of sodium chloride, most preferably between 200 and 300 gm per litre The solution is, further, preferably saturated with chlorine. The amount of the aqueous chlorine-containing solution can be varied

within wide limits Generally, each 30-150 kg of the hydroxides require at least 500 litres of the aqueous solution in order to assure dissolution of all of the trivalent nickel hydroxide, although the amount of course depends upon the amount of trivalent nickel hydroxide in the mixture of trivalent nickel and cobalt hydroxides There is actually no maximum amount of solution which may be used, although as a practical matter, in order to avoid the necessity of extremely large apparatus, the amount of solution should not exceed 3000 litres per 30-150 kg of the hydroxides Most preferably, between 1500 and 2000 litres per 30-150 lg is utilised. The extraction is preferably carried out at a temperature between 50-100 ' C, and most preferably between 90-95 C. As stated previously the extraction treatment results in dissolution of the trivalent nickel hydroxide in the chlorine-containing solution, while the trivalent cobalt hydroxide remains undissolved The leaching or extraction of the mixed hydroxides can be carried out until the regular control sample of the bottom residue, depending upon the requirements of the opezation shows only traces of the nickel, or until the leached product is free of nickel. The method of the invention allows separation of the nickel from the cobalt to a degree of 100 %, so that in the nickel solution no cobalt is present as shown by means of -tnitroso-r J-naphthol, while in the cobalt residue no nickel is present as can be shown by means of dimethyl-glyoxime. The oxidation is preferably carried out in a vessel provided with a stirrer in which the mixed hydroxide is stirred with the small amount of oxidising solution in the form of a slurry until the desired conversion of the nickel and cobalt into the trivalent form is achieved. The leaching or extracting of the trivalent nickel hydroxide from the trivalent cobalt hydroxide is carried out in suspension, generally in a larger amount of liquid, and can also be carried out in vessels provided with stirrers, although to improve the extraction it is also possible to operate in an autoclave under pressure. The extracted very pure nickel solution or the remaining very pure cobaltic hydroxide can be worked up by any suitable means into pure salts, oxides, catalysts, reducing metals, hard metals electrolyte metals or metal eo ders: the aenus chlorin ontanna rolu tion, which will generally also contain a carrier salt, such as the sodium chloride, can be recovered and/or recirculated for further extraction. The following examples further illustrate the method of the present invention:EXAMPLE 1 kg of mixed hydroxides of cobalt and nickel including divalent and trivalent hydroxides of each (the ratio of cobalt to nickel bns 10: 1) are introduced into a container and no o

of tanr water e On amnt sufficient to form only a slurry, is added The resulting slurry is subiected to an oxidising treatment in wvvhich, while stirrin T at room temperature, chlorine gas in fine subdivision is introduced into the slurry until the metal hydroxide mixture has a black colour throuwh and= through, Indicating that both the nickel and the cobalt are in trivalent form. The oxidised slurry is then introduced into a centrifuge and there the solid particles are separated from the liquid by centrifuging The spent liquor can serve for the treatment of friesh raw material. 3000 litres of tap water containing about 300 g/l of Na Cl, which serves as a carrier salt for chlorine gas and also to aid in the extraction. is heated to a temperature of 45-50 C in a 37/ cubic metre vessel Chlorine gas is then introduced into solution until the solution has an intense yellow colour and shows an acid reaction The temperature is then increased to 90-95 C. The extraction treatment is then carried out as follows: The mixture of trivalent cobalt and nickel obtained by the oxidation of the kg of the mixed hydroxides, wvhich trivalent compounds are in the form of a I SO kf. cake, are added to the solution slowly while stirring After the introduction is completz the leaching is continued for 30 minutes at 90-95 ' C and thereafter the original content of chlorine gas in the aqueous solution is restored Alternate periods of 30 minutes extraction and renewed addition of chlorine gas are continued until the desired purity of the cobalt hydroxide is achieved The senaration of the mother liquor, and also of the wash 785,350 water obtained in a later stage, from the cobaltic hydroxide residue is carried out by centrifuging The nickel-containing liquor and the cobaltic hydroxide can be further worked up to the desired end product; the wash water can be utilised for treatent of additional raw material. EXAMPLE 2 kg of a mixture of cobalt and nickel divalent and trivalent hydroxides (ratio of cobalt to nickel being 1: 1) are introduced into a container with only so much tap water as will form a slurry, i e with 60 kg of tap water The resulting slurry is subjected to an oxidation treatment which comprises stirring the slurry at room temperature and simultaneously introducing chlorine gas in finest subdivision until the metal hydroxide mixture has a black colour through and through, indicating the trivalent form of the metals. This mass is introduced into a centrifuge and there subjected to centrifing The spent liquor can serve for the treatment of fresh raw material. 3000 litres of tap water containing about 240 g/l of Na Cl, which serves as a carrier salt for chlorine gas and to improve the

extraction, is heated in a 32 cubic metre vessel to a temperature of 60-65 ' C Chlorine gas is then introduced until the solution has an intense yellow colour and gives an acid reaction The temperature is then raised to between 85900 C. The extraction is then carried out by the addition of the mixed trivalent hydroxides to the solution slowly while stirring After the introduction of all the hydroxides the leaching is continued for 20 minutes at 85-90 C and thereapon the solution is again saturated with chlorine gas. Alternate 30-minute extractions and renewed additions of chlorine gas are continued until the desired purity of the cobaltic hydroxide has been obtained The separation of the original nickel mother liquor, and of the wash water obtained in the later stages, from the cobaltic hydroxide is accomplished by means of a centrifuge. An important advantage of the method of the present invention is that it can be carried out with any ratio of cobalt to nickel or nickel to cobalt without any important changes in the method of procedure being necessary An additional important advantage of the method of the present invention is that it can be carried out without the necessity of carefully controlling the pi and maintaining the p H within narrow limits Therefore, the method of the present invention permits much easier operation than known methods.

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* GB785351 (A)

Description: GB785351 (A) ? 1957-10-30

Substituted propionaldehydes

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

COMPLETE SPECIFICATION Substituted Propionaldehydes We, MERCK & Co., INC., a Corporation duly organised and existing under the Laws of the State of New Jersey, United States of America, of Rahway, New jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention is concerned with novel derivatives of propionaldehyde. In brief, this invention provides 2-halo 3,3-dialkoxy-propionaldehydes and 2-halo3,3-diaralkoxy-propionaldehydes which mav be represented by the general formula RRCHCHX.CHX.CHO in which R is an alkoxy or aralkoxy radical and X is a halogen atom. The novel compounds are useful in a synthesis of pteroylglutamic acid. They are starting materials in the process of our copending Application No. 18454/56 (Serial No. 785,353), the products of which may be converted to pteroylglutamic acid by the processes described and claimed in the specification of our expending Applications Nos. 18455/56 and 18456/56 (Serial Nos. 785,354 and 785,355). Pteroylglutamie acid, or vitamin Be, occurs naturally in yeast, liver, grasses and mushrooms. This substance has been found to be therapeutically effective in the treatment of macrocytic anaemias, sprue, and other conditions of the circulatory system. Although pteroylglutamic acid can be isolated from natural sources, it has been found that chemical synthesis of the vitamin is a more desirable method of production. However, the synthesis of pteroylglutamie acid reported heretofore have not been entirely satisfactory due to low yields and inherent difficulties caused by the very low solubility of the intermediates produced. According to the present invention, a 1,2-dihalo-1,3,3-trisubstituted propane in which the 1,3,3 substituents are alkoxy or aralkoxy radicals, is reacted with a weak base, preferably in the presence of

an inert solvent, to produce the corresponding 2-halo-3,3-(dialkoxy or diaralkoxy)propionaldehyde. This reaction can be illustrated as follows RRCH.CHX.CHX.R # RRCH.CHX.CHO X being a halogen and R an alkoxy or aralkoxy radical. The starting materials which can be used in practising this invention are the 1,2.dihalo.1,3,3-trialkoxy.propanes and the 1,2-dihalo-1,3,3-triaralkoxy-propanes. Such compounds are readily prepared by halogenating a 1,3,3-(trialkoxy, or triaral- koxy)-propylene-1. For example, 1,2dibromo-1,3,3-tribenzyloxy-propane is prepared by reacting acrolein dibromide with benzyl alcohol in the presence of hydrochloric acid to form 2-bromo-1,3,3-tribenzyloxy-propane, which is then reacted withan inorganic base in the presence of benzyl alcohol to produce 1,3,3-tribeuzyl. oxy-propylene-1. This is then readily brominated to the desired 1,2dibromo- 1,3,3-tribenzyloxy-propane. Other compounds which can be prepared according to this method are 1,2-dichloro-1,3,3trimethoxy-propane, 1,2-dichloro-1,3,3tributoxy-propane, 1,2-dibromo-1,3,3triethoxy-propane, 1,2-dichloro-1,3,3triethoxy-propane, and 1,2-dibromo-1,3,3tripropoxy-propane. After the reaction has been terminated the 1,2-dihalo-1,3,3trisubstituted propane can be isolated from the reaction mixture and purified, or the reaction mixture can be used directly as the starting material in the process of the invention without further processing. In the process according to this invention, a 2-halo-3,3-(dialkoxy or diaralkoxy)propionaldehyde is produced by reacting the corresponding 1,2-dihalo-1,3,3-(trialkoxy or triaralkoxy)-propane with a weakly basic substance. Examples of weak bases which are suitable for effecting the reaction are sodium acetate, sodium bicarbonate, and ammonium hydroxide. The reaction is conveniently conducted in the presence of a suitable inert solvent or mixture of solvents. In general, hydroxy- lated solvents such as the alcohols are not used as the reaction medium since snail solvents are not completely inert under the conditions of reaction. Some examples of solvents which can be used are water, dioxan, ether, chloroform, carbon tetrachloride, acetone, benzene and formamide. The reaction proceeds satisfactorily within a wide range of temperatures. Thus lowered temperatures of about 100C., and elerated temperatures such as 800 C., can be used with good results. The resulting 2-halo-3,3-(dialkoxy or diaralkoxy)propionaldehyde can be

recovered from the reaction mixture by conventional methods. Examples of the novel compounds which can be prepared by this process are 2-bromo-3,3-diethoxy-propionaldehyde, 2-bromo-3,3-dibenzyloxy-propionaldehyde, 2-chloro-3,3-dipropoxy-propionaldehyde, and 2-bromo-3,3-dibutoxypropionaldehyde. The examples which follow illustrate methods of tarrying out the present invention. EXAMPLE 1 Production of 2-bromo-3,3-diethoxy propionaldehyde 100 g. of 1,2-dibromo-1,3,3-triethoxypropane was added to a solution of 27.6 gm. of sodium bicarbonate in a mixture of 30 ml. of water and 90 ml. of dioxan at a temperature below 100 C. After all the 1,2-dibromo-1,3,3-triethoxy-propane was added, stirring was continued for 2 honrs. The reaction mixture was extracted with ethyl ether and the ether extract washed with water and dried over anhydrous sodium sulphate. The ether solution was filtered and concentrated on a steam bath under reduced pressure to remove the solvent. The resulting liquid was frac- tionated through a distillation column. The vield was 26 gm. of 2-bromo-3,3diethoxy-propionaldehyde having a boiling point of 630-650C., at 2.5 mm. of mercury and a refractive index of 23.20 C. 1.4513 at N D The 1,2-dibromo-1,3,3-triethoxy-propane used as the starting material was prepared by reacting 50 gm. of 1,3,3-triethoxy-pro- pylene-1 in 125 ml. of ether with 41 gm. of bromine while stirring and maintaining the temperature between 00-100C. The solution was stirred for 1 hour at 0 -10 C., and then the solvent removed under reduced pressure to produce a residue of 1,2-dibromo-1,3,3-triethoxy-propane. EXAMPLE 2 Production of 2-chloro-3,3-diethoxy propionaldehydc To a 100 ml. 3-necked flask equipped with stirrer, thermometer, and gas inlet was added 34.8 gm. of 1,3,3-triethoxy- propylene-1. It was cooled with stirring to about 5 C., and then 13.6 gm. of chlorine was bubbled through the liquid over a period of 45 minutes. The reaction mixture containing 1,4- lichloro-1,3,3- triethoxy-propane was then added under nitrogen and with stirring to a mixture of 21 ml. of water, 62.5 ml. of dioxan. and 96.4 gm. of sodinm bicarbonate. The reaction mixture was maintained at 5 -10 C., and stirred for 2 hours.

The reaction mixture was extracted twice with 50 ml. portions of ether. The combined ether extracts were washed with water and dried over sodium sulphate. The ether solution was filtered and removed under reduced pressure. The residue was dis- tilled over calcium carbonate under reduced pressure to give 2-chloro-3,3- dietlioxy-propionaldehyde having a boiling point of 58 -60 C., at 1.2 mm. of mereury 25 and a refractive indes of 1 4309 at N D. In the same manner, 2-chloro-3,3dipropoxy-propionaldehyde, 2-chloro-3,3dibenzyloxy-propionaldehyde and 2-chloro3,3-dibutoxy-propionaldehyde can be prepared by employing the corresponding 1,2-dichloro substituted propane. What we claim is 1. A 2-halo-3,3-di-R-propionaldehyde, in which R represents an alkoxy or aralkoxy radical. 2. 2 - Promo - 3,3 - diethoxy-propiollalde- hyde. 3. 2-Chloro - 3,3 - diethoxy-propionaldehide. 4. The method of producing a 2-halo3,3-di-R-propionaldehyde which comprises reacting a 1,2-dihalo-1,3,3-tri-R-propane with a weak base in the presence of an inert solvent, where R represents an alkoxy or aralkoxy radical. 5. The method of pro(iucig io-bromo- 3,3-diethoxy-propionaldehr de which comprises reacting 1,9-dibromo-1,3,3-triethox~v- propane lvith a weak base in the presence of an inert solvent. 6. The method of producing 2-chloro3,3-diethoxy-propionaldehyde which comprises reacting 1,2-dichloro-1,3,3-triethoxypropane with a wreak base in the presence of an inert solvent. 7. A process according to Claim 4,

* GB785352 (A)

Description: GB785352 (A) ? 1957-10-30

Preparation of pteridine derivatives

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PATENT SPECIFICATION 7859352 ' Date of Application and filing Complete Specification: Oct 18, 1954. No 29965154. Application made in United States of America on Oct 21, 1953. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 2 ( 3), C 2 A( 3: 7), C 2 86 (A 4: B: D: F: J), C 2 837 (A 3: B 3: Cl: C 4: D 3: J: K: L), C 2 D 3, C 2 R 16. International Classification:-CO 7 d. COMPLETE SPECIFICATION Preparation of Pteridine Derivatives We, MERCK & CO, INC, a corporation duly organised and existing under the laws of the State of New Jersey, United States of America, of Rahway, New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to methods useful in the production of substituted pteridines. The presently available processes for the production of substituted pteridines, such as pteroylglutamic acid (folic acid), are difficult to carry out and generally result in poor yields of the desired product. In accordance with the present invention, it is now found that pteridines having a formyl substituent in the pyrazine ring can be condensed with aromatic amines in the presence of a compound containing a sulphhydryl group to produce the corresponding pteridyl methylene amine This reaction may be illustrated as follows: CEO + Ar NE 2 -S Ha C o CH 2 N 2 r where Ar represents an aromatic radical which may be substituted or unsubstituted This method of condensing pteridine aldehydes with aromatic amines provides a convenient and practical method of preparing substituted pteridines. I Thus, pursuant to a preferred embodiment of this invention, valuable substituted pteroic acid compounds and derivatives thereof such as folic acid can be readily prepared in accord 35 ance with the following reaction:

R Rt HN i ay C 17 R II | (-SH) 0CH 2 NH i 1 Ri RIE' wherein R is a hydroxy group or group convertible to hydroxy by hydrolysis such as an alkoxy, aryloxy or aralkoxy group, R 1 is hydrolPrice 3 s 6 d l III gen or an acyl group and RW 1 is a hydroxy, alkoxy, aryloxy, aralkoxy, amino or substituted amino group. These substituted pteridines are conveniently produced according to this invention by contacting a pteridine aldehyde and aromatic amine in the presence of a compound having a sulphhydryl group Some of the sulphhydryl compounds that are particularly useful in effecting this reaction are those in which the sulphhydryl group is attached to an aromatic ring, such as 13-thionaphthcl, p-thiccresol and thiophenol, but other sulphhydryl compounds such as thiourea, thioacetic acid thioglycollic acid, hydrogen sulphide, benzylmercaptan and tertiary butylmercaptan are also suitable. As has been briefly indicated above, aromatic amines and particularly para-aminobenzoic acid and derivatives thereof such as esters and amides may be condensed with pteridine aldehydes in the presence of a sulphhydryl compound to produce the desired pteridine derivatives For example, alkyl, aryl, and aralkyl esters such as methyl, ethyl, propyl, butyl, phenyl and benzyl esters of para-aminobenzoic acid and amides such as para-aminobenzamide and similar amides derived from para-aminobenoic acid and amino acids such as glutamic acid, glycin-, aspartic acid, leucine alanini and cysteine may be used as reactants in this process. The pteridine aldehydes suitable for use as reactants in this process may have the aldehyde group in the 6 or 7-position of the pteridine ring This process, however, is particularly suitable for effecting the condensation of pteridine aldehydes which have an aldehyde group in the 6-position of the pteridine ring with suitable aromatic amines In this regard, the condensation of an appropriate aromatic amine with 6-formyl-pteridines, and particularly 2amino-6-formyl-pteridines and 2-acylamino6-formyl-pteridines having a hydroxy group or a group convertible to hydroxy by hydrolysis in the 4-position, results in the formation of products such as pteroic acid, folic acid and similar compounds of established value and great usefulness Alternative to having a hydroxy group in the 4-position such pteridine aldehydes may have groups at this position which are equivalent to the hydroxy group such as alkoxy, aryloxy and aralkoxy groups and specifically methoxy, ethoxy, propyloxy, phenoxy and benzoyloxy groups. The 2-amino pteridines described above may be conveniently produced by processes described in the literature while the 2-acylamino6-formyl-pteridines such 2-propionamido-4hydroxy-6-formyl-pteridine, 2-benzamido-4hydroxy-6-formiyl-pteridine,

2-butyramido-4hydroxy-6-formyl-pteridine and 2-phenylacetamido-4-hydroxy-6-formyl pteridine are claimed in and may be conveniently produced by processes described and claimed in the specification of our copending application No. 18454/56 (Serial No 785,353). The 2-acylamino-pteridines offer many advantages over the non-acylated 2-amino compounds and are therefore preferred for use in this process Thus, one advantage realized when the 2-acylamino-pteridines are utilized in this process is the obtainment of essentially pure condensation products directly from the reac 70 tion mixture with a minimum of effort. Furthermore, the 2-acylamino-pteridines have a solubility considerably greater than that of the 2-amino-pteridines and, accordingly, may be employed in this process in greater concen 75 trations than the non-acylated compounds with an appreciable saving of solvent. To effect the process of this invention the pteridine aldehyde and aromatic amine are conveniently contacted with a sulphhydryl com 80 pound in the presence of an inert solvent. Among the solvents which may be used for this purpose that can be mentioned are Cellosolhe, Methtylcellosolve, Butylcellosolve, pyridine, acetic acid, dioxane and substituted 85 methylamines (Cellosolve is a registered Trade Mark). The condensation begins immediately upon contacting the reactants and sulphhydryl compound in a solvenit but nevertheless proceeds 90 slowly at ordinary temperatures To increase the reaction rate and hasten its completion elevated temperatures of about 100-170 C, and preferably the reflux temperature, may be conveniently used The time required to com 95 plete the reaction will naturally vary somewhat with the reactants and reaction conditions but ordinarily reaction times of 2 to 16 hours are entirely adequate. In effecting the reaction by the novel method 100 of this invention various ratios of pteridine aldehyde to aromatic amine can be employed successfully However, it is considered preferable to employ equimolar amounts of the reactants, or a slight excess of the aromatic 105 amine, since good results are obtained with such quantities The sulphhydryl compound is preferably used in excess To obtain optimum results, a twofold to twelvefold molar excess, based on the amount of pteridine alde 110 hyde, is used. After the reaction has been completed the desired pteridine condensation product is isolated from the reaction mixture by conventional procedures Thus, the pteridine deriva 115 tives which are generally of low solubility in organic solvents are accordingly readily recovered by filtration and purified by washing with solvents such as ether and water Alternatively, a solvent such as ether or

water in 120 which the product is insoluble may be added directly to the reaction mixture to insure complete precipitation of the product. As is seen from the above description this process may be applied in the production of a 125 large number of valuable substituted pteridines. Nevertheless, this process is considered to be extremely useful in the commercial production of folic acid and its related N 2-acylamino derivatives By this process, the condensation of 130 785,352 manner using other sulphhydryl compounds such as thiophenol, thioglycollic acid, thiourea and /-thionaphthol and solvents such as dioxane, tetrahydropyran, pyridine and acetic acid. 2-amino and 2 acylamino-4-hydroxy-6formyl-pteridines with para-aminobenzoylglutamic acid in the presence of a sulphhydryl compound produces folic acid and N 2-acylfolic acids in greater yield than has been previously obtained In addition, the resulting folic acid products are much purer and in crystalline form Such results are indeed surprising in view of the many difficulties normally encountered i O in the pteridine art in obtaining essentially pure crystalline compounds. EXAMPLE 1. A mixture of 1 34 g of 2-acetamido-4hydroxy-6-formyl-pteridine, 2 0 g of p-aminobenzoylglutamic acid, 5 0 g of p-thiocresol and 50 ml of Met hylcellosolve is heated at reflux temperature for 31 hours The dark red reaction mixture is cooled to room temperature and added to 250 ml of absolute ether with stirring After stirring for 10 minutes the N 2acetyl-pteroylglutamic acid is filtered, washed thoroughly with ether and dried under reduced pressure at room temperature The product so obtained assays 65 5 % folic acid by the Bratton-Marshal chemical assay which is set forth in the Folic Acid section of the U S. Pharmacopoeia, 15th Rev ( 1955), pp 298299, and 64 % folic acid by the bioassay using L casei as test organism. Esters of N'-acetyl-pteroylglutamic acid are obtained by utilizing esters, such as the ethyl, propyl and benzyl esters of p-aminobenzoylglutamic acid as reactants. EXAMPLE 2. A mixture of 1 6 g of 2-acetamido-6hydroxy-6-formyl-pteridine, 2 0 g of paminobenzoylglutamic acid, 1 8 g of thiourea and 50 ml of Cellosolve is refluxed for 3 hours. The mixture is cooled to room temperature and added to 250 ml of absolute ether with stirring. The brown precipitate of N 2-acetyl-pteroylglutamic acid is filtered, washed with ether and dried Without further purification it assays 20.4 % folic acid by chemical assay. This process is repeated using thioacetic acid, /B-thionaphthol,

benzylmercaptan, tbutylmercaptan and hydrogen sulfide in place of thiourea to produce N 2-acetyl-pteroylglutamic acid. EXAMPLE 3. A mixture of 1 31 g of 2-amino-4-hydroxy6-formyl-pteridine, 2 1 g of p-aminobenzoylglutamic acid, 2 5 g of thiocresol and 50 ml. of Cellosolve is heated at reflux for 13 hours. The mixture is cooled to room temperature and filtered to remove unreacted 2-amino-4hydroxy-6-formyl-pteridine The filtrate is diluted with absolute ether to yield a redyellow precipitate of pteroylglutamic acid which is removed by filtration, washed with ether and dried at room temperature under reduced pressure It is found to contain 37 % folic acid by chemical assay and 46 % folic acid by microbial assay. Pteroylglutamic acid is also produced in this EXAMPLE 4. A mixture of 0 5 g of 2-acetylamino-4hydroxy-6-formyl-pteridine, 0 7 g of p-aminobenzoylaspartic acid and 1 g of benzylmercaptan are refluxed in 50 ml of pyridine for 75 hours The mixture is cooled, ether is added and the product consisting of N 2-acetyl-pteroylaspartic acid is recovered by filtration. In the same manner other amides of paminobenzoic acid with amines such as glycine, 80 alanine, leucine and cysteine may be reacted with 2-acetylamino-4-hydroxy-6-formyl-pteridine to produce the corresponding derivatives of N 2-acetyl pteroic acid. EXAMPLE 5 85 A mixture of 1 g of p-aminobenzamide, 1.2 g of 2-acetylamino-4-hydroxy-6-formylpteridine and 2 g of thiourea is refluxed in ml of dioxane for 12 hours After cooling ether is added to the mixture and the N 90 acetyl-pteranide recovered by filtration. EXAMPLE 6. A mixture of 0 7 g of ethyl p-aminobenzoate, 1 0 g of 2-amino-4-hydroxy-6-formylpteridine and 1 5 g of thiocresol is refluxed in 95 Cellosolve for 15 hoursl, cooled, ether added and the ethyl pteroate recovered by filtration. This reaction is repeated with other esters of p-aminobenzoic acid such as the methyl, propyl, phenyl and benzyl to produce the cor 100 responding esters of pteroic acid. EXAMPLE 7. A mixture of 1 g of 2-acetylamino-4hydroxy-6-formyl-pteridine, 0 6 g of p-aminobenzoic acid and 1 4 g of I?-thionaphthol are 105 added to 100 ml of pyridine and refluxed for 14 hours The mixture is cooled and ether added to precipitate N 2-acetyl-pteroic acid. The product is filtered and dried. EXAMPLE 8 110 To a 500 ml three-necked flask equipped with stirrer, condenser,

nitrogen inlet and thermometer are added 6 7 g of 2-acetamido4-hydroxy-6-formyl-pteridine, 10 g of paminobenzoyl glutamic acid, 25 g of p-thio 115 cresol and 250 ml of Methyleellosolsve The flask is flushed with nitrogen and the mixture is heated rapidly to the reflux temperature with stirring The solution is refluxed under nitrogen for 31 hours during which time the colour 120 changes from yellow to orange to a dark reddish brown A gelatinous precipitate forms during this period and the viscosity of the mixture increases. After completion of the refluxing, the re 125 action mixture is poured into 3500 ml of rapidly stirred hot water The reaction flask is rinsed with 200 ml of hot water which is added to the batch The resultant mixture is heated at 100 C with stirring until removal 130 785,352 of thiocresol is complete This requires about minutes 500 ml of distillate is obtained consisting of a mixture of thiocresol and water. The undistilled residue remaining after distillation is filtered while hot and the darkcoloured filtrate is allowed to cool slowly to room temperature The mixture is then chilled in an ice-bath and filtered The solid N'-acetylfolic acid thus obtained is washed with acetone and ether and dried at 800 C It weighed 7 5 g. and assayed as 92 % acetyl-folic acid by the Bratton-Marshall method. The N 2-acetyl-folic acid is readily converted to folic acid itself by treatment with a 0 1 N solution of sodium hydroxide at 90 C for 30 minutes The folic acid obtained after decolorization with charcoal and acidification to p H 3 with hydrochloric acid is essentially pure.

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