Fluid sodium or potassium phenyl-glycine salt prepn. - by saponifying nitrile deriv. with mother liquors from alkali hydroxide and amide melts

摘要

Fluid alkyl metal salts of phenylglycine and of phenylglycine-o-carboxylic acid are prepd. by (a) the stepwise saponification of the corresponding nitriles with aq. alkaline waste mother liquors, in the presence of aniline, at between 50 degrees C and b.pt. and (b) evaporation of the reaction mixt. The mother liquors are obtd. from alkali hydroxide/alkali amide melts and contain (by wt. wrt mother liquor) 7-30% NaOH/KOH mixt., 20% Na2CO3/K2CO3 and opt. 10% other components, in addition to smaller quantities of coloured components and organic decompsn. prods. The phenylglycine salt is used as the raw material for indigo prepn. Fluid, mixed phenylglycine salts are obtd. which form less dust in use than Na salts, prepd. by saponifying with NaOH solutions. Use of waste solutions reduces environmental pollution.