2-Aminophenol → 2H-1,4-Benzoxazine

Participants

Reaction Steps

To a mixture of 2.29 g (21.0 mmol) of o-aminophenol in 25 mL of dry toluene was added portion wise 11 mL of 2N oxalyl chloride/CH2Cl2 (22.0 mmol) solution. The mixture was refluxed for 4 h, cooled to room temperature, filtered and the solid was washed with xylene and water, and dried to leave 3.10 g (90%) of 2a as pale-green solid. The analytical sample was obtained by crystallization from acetone, mp 263°-264° C. (lit, 264°-266° C.; Bernard et al, J. Med. Chem. 28:240 (1985)). 1H NMR (CDCl3 +DMSO-d6), 6.932 (m, 4), 11.970 (m, 1).

Provenance & Evidence