ENZYMATIC SYNTHESES OF N-LAUROYL-BETA-ALANINE HOMOLOGS IN ORGANIC MEDIA

Enyzmatic amidation of the primary amines beta-alanine ethyl ester and 3-aminopropionitrile with methyl laurate by means of immobilized lipa se (Candida antarctica lipase, CAL) resulted in the formation in good yield of N-lauroyl-beta-alanine ethyl ester and 3-(N-lauroylamino)-pro pionitrile, respectively. When 3-amino-propionitrile was used as subst rate, diisopropyl ether was a suitable solvent. Changing the reaction temperature (12-80 degrees C) did not affect the yields, and room temp erature was a suitable temperature for this reaction. In the investiga tion of reaction conditions, the use of equimolar amounts (5 mmol) of substrate and ester, along with 0.5 g of CAL, in diisopropyl ether gav e the best yield (99.3%) alter 24 h of incubation at 24 degrees C. The enzyme activity in the amidation reaction did not decrease even after six uses. With beta-alanine ethyl ester hydrochloride as substrate, d iisopropyl ether was unsuited as a solvent owing to the low solubility of the substrate in this solvent.In this reaction, the best yield (82 .0%) was attained by using dioxane as solvent. CAL achieved higher ext ents of amide synthesis with long-chain than with short-chain ester su bstrates. The enzyme accepted only nonbulky primary amines as substrat es.