Acetic Anhydride → 7-Methyl-2-(2-oxopropyl)-4H-3,1-benzoxazin-4-one

Participants

Reaction Steps

A mixture of 4-methylanthranilic acid (25.0 g., 0.17 mole) and diketene (13.95 g., 0.17 mole) in CCl4 (250 ml.) was heated at reflux for 2.5 hours. Acetic anhydride (18.3 g., 0.18 mole) was added and the mixture was stirred under reflux for 16 hours. The mixture then was cooled and the product isolated by filtration; upon recrystallization there was obtained 2-acetonyl-7-methyl-4H-3,1-benzoxazin-4-one (17.4 g., 48 percent), mp 142°-144° C.

Provenance & Evidence