A new convenient method for the synthesis of 2H‐1,4‐benzoxazine derivatives from nitroketones via intramolecular reductive cyclization

Abstract

Dedicated to Professor Herbert C. Brown on the occasion of his 90th birthday. Potentially bioactive 2H‐1,4‐benzoxazine derivatives could be conveniently prepared in one step from the corresponding nitroketones using 10% palladium on carbon with triethylamine in the presence of hydrogen (Pd/C‐TEA‐H2) system. Several other tertiary amines such as nicotine, pyridine, and quinoline also could be used, but TEA gave the best results.