PROCESS FOR THE PREPARATION OF ORGANIC INTERMEDIATE

摘要

5-methyl-3-carbamoyl-iso-oxazole of formula (I) is prepd. as follows: Methyl-ester of acetyl-pyruvic-acid of formula (III) is obtd. by base catalysed condensn. of oxalic-acid-di:tert-butyl-ester or oxalic-acid-di:iso-butyl-ester and acetone. (III) reacts with hydroxyl-amine-sulphate or hydroxylamine-hydrochloride to yield 5-methyl-iso-oxazole-3-carboxylic-acid-methyl-ester of formula (IV), (IV) reacts with ammonia by known means without being isolated or purified.