PROCESS FOR PREPARATION OF ARYL METHYL MALONIC ACIDS

1,139,786. Preparation of arylmethyl malonic acids. KALLE A.G. 24 Nov., 1967 [26 Nov., 1966], No. 53598/67. Heading C2C. Arylmethyl malonic acids are prepared by condensing an arylaldehyde with malonic acid in the presence of an acid chloride (e.g. acetyl chloride or thionyl chloride) to form the corresponding arylmethylene malonic acid, which is hydrogenated. The preferred hydrogenation procedure, is to treat an aqueous solution of a mono- or di-alkyl metal salt of the arylmethylene malonic acid containing a nickel catalyst, with hydrogen. In the example, benzaldehyde is condensed with malonic acid to form benzal malonic acid, which is added to a sodium hydroxide solution and the resultant salt solution hydrogenated as specified above. The benzylmethyl malonic acid is obtained by acidifying the solution. The preparation of 4- methyl-benzal- and 4- methyl-benzyl-malonic acids, 4-methoxy-benzal- and 4-methoxy-benzyl-malonic acids and 4-chloro-benzal- and 4- chloro-benzyl-malonic acids is specified.