2-Aminophenol → 1,4-Benzoxazine-2,3-dione

Participants

Reaction Conditions

Reaction Steps

Ortho-aminophenol (21.8 g) in 200 ml of ortho-dichlorobenzene was added as a slurry to 18.3 ml oxalyl dichloride (1.05 mol eq) in 150 ml ortho-dichlorobenzene at about 100° C. with stirring. After the addition (about 30 min.), the reaction mixture was heated to about 70° C. and then kept at this temperature for approximately 1.5 hours. The reaction mixture was then cooled, filtered and the solid product, 4H-1,4-benzoxazin-2,3-dione was washed with ether to give 27 g., m.p. 265°-268° C.

Provenance & Evidence