Formaldehyde → 4-oxo-4H-3,1-benzoxazine-8-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

2-Aminoisophthalic acid moiety (50.0 g; 276.0 mmol) and formaldehyde (250.0 ml; 5.00 V) were combined and heated to 140° C. for 4 h. The reaction mixture was cooled to room temperature and distilled under high vacuum on the rotary evaporator. The remaining formaldehyde was removed by azeotropic distillation with toluene. The residue was slurried with ethyl ether, filtered, and the solid was dried under vacuum to provide the desired intermediate (50.3 g, 89% yield).

Provenance & Evidence