Investigations on pyrazine derivatives. VII: On the conversion of pyrazine 2,5‐dicarboxylic acid into some derivatives of 2‐aminopyrazine 5‐carboxylic acid

Abstract

Abstract Pyrazine 2,5‐dicarboxylic acid was prepared by oxidation of 2,5‐dimethylpyrazine with selenium dioxide. 2,5‐Diethoxycarbonylpyrazine appeared to be a suitable starting‐material for the preparation of monocarbamoyl‐ and monocarboxyhydrazide derivatives. Hofmann degradation of 2‐carbamoyl‐5‐ethoxycarbonylpyrazine into 2‐aminopyrazine 5‐carboxylic acid proved to be rather difficult. The monocarboxyhydrazides in this series could be readily converted into acid azides and eventually into pyrazine‐urethanes.