Front Cover: Synthesis of 2H-1,4-Oxazin-3(4H)-One Utilizing Umpolung Reaction to α-Hydrazonoketone (Asian J. Org. Chem. 3/2025)

Abstract

α-Hydrazonoketone was found to be an appropriate substrate for umpolung N-alkylation with Grignard reagents. The reaction proceeded extremely fast under mild reaction conditions. Especially, N-methylation was completed for only 30 seconds to afford the N-methylated product in quantitative yield. Tandem N-alkylation/reduction/N-acyl-O-alkylation with chloroacetyl chloride was also developed. This led to an efficient synthesis of a 2H-1,4-oxazin-3(4H)-one in good yield. More details can be found in article number e202400698 by Isao Mizota and co-workers.