CHEMICAL CONSTITUTION AND SYNTHESIS 



hydrolysis of the strychnine D-lactone sulphate to the optically active 

 lactone. Merck & Co.^^a ^gg^j brucine for resolving pantolactone. 



Parke, Davis & Co./^ patented the preparation of pantolactone by 

 the interaction of formaldehyde, isobutyraldehyde, sodium cyanide 

 and sodium bisulphite, giving jS-hydroxy-aa-dimethylpropionaldehyde 

 cyanhydrin, which yielded pantolactone on acid hydrolysis. 



Preparation of (^-Alanine and its Esters 



A large number of methods have been described for the preparation 

 of j3-alanine and its esters. F. Weygand ** prepared jS- alanine ethyl 

 ester by hydrogenation of ethyl cyanacetate in presence of platinum 

 oxide, whilst Lederle Labs., Inc. prepared /3-alanine itself by hydro- 

 genating cyanacetic acid in presence of platinum oxide or palladium,*^ 

 or by hydrogenating cyanacetamide and hydrolysing the resulting 

 j3-alanine amide. *^ National Oil Products Co.*'^ hydrogenated methyl 

 or ethyl cyanacetate in presence of sulphuric acid, whilst F. Hoffmann- 

 La Roche & Co.*^ hydrogenated potassiimi cyanacetate in ammoniacal 

 solution, using a nickel catalyst. Lederle Labs., Inc. prepared /3-alanine 

 by the addition of ammonia to acrylonitrile at 150° C.*^ or to a salt 

 of acrylic acid.^^ It has also been prepared by the action of ammonia 

 on bis-j3-cyanoethylamine,^i on thiodihydroacrylonitrile,^^ on ethylene 

 cyanhydrin ^^ and on j8-alkoxypropionitriles.^* 



A. Galat ^^ prepared jS-alanine by the addition of phthalimide to 

 acrylonitrile, followed by acid hydrolysis of the ^-phthalimidopro- 

 pionitrile. |8-Alanine hydrochloride was converted into ^-alanine by 

 the use of lithium hydroxide. A variant of this method is to fuse 

 phthalic acid or anhydride with an ester of ^j8'-imino-dipropionic 

 acid capable of forming a volatile acrylic ester and hydrolysing the 

 phthalimido-propionic ester so formed. ^^ Finally, esters of jS-alanine 

 can be prepared by redaction of nitropropionic esters.^' 



References to Section 3 



1. R. J. Williams, H. H. Weinstock, E. Rohrmann, J. H. Truesdail, 



H. K. Mitchell and C. E. Meyer, /. Amer. Chem. Soc, 1939, 61, 



454- 



2. R. J. Williams and R. Moser, ibid., 1934, 56, 169. 



3. H. K. Mitchell, H. H. Weinstock, E. E. Snell, S. R. Stanbery and 



R. J. Williams, ibid., 1940, 62, 1776. 



4. E. T. Stiller, J. C. Keresztesy and J. Finkelstein, ibid., 1779. 



5. R. J. WiUiams, H. K. Mitchell, H. H. Weinstock and E. E. Snell, 



ibid., 1784. 



6. S. H. Babcock and T. H. Jukes, ibid., 1628. 



7. E. T. Stiller, S. A. Harris, J. Finkelstein, J. C. Keresztesy and 



K. Folkers, ibid., 1785. 



357 



