Acetic Anhydride → 5-Chloro-2-methyl-4H-3,1-benzoxazin-4-one

Participants

Reaction Conditions

Reaction Steps

2-amino-6-chlorobenzoic acid (25 g) dissolved in acetic anhydride (100 ml) was stirred at 120° C. for 2 hours. The mixture was cooled to room temperature and filtered off. The precipitate was washed with water and Na2CO3 (10%) and dissolved in CH2Cl2. The solution was dried with Na2SO4, filtered off and evaporated. The residue was crystallized twice from benzene, yielding 13 g (46%) of 5-chloro-2-methyl-4H-3,1-benzoxazin-4-one; mp. 148.7° C. (interm. 14).

Provenance & Evidence