1,2-Dichloroethane → 6-Methyl-2-(4-phenoxyanilino)-3,1-benzoxazin-4-one

Participants

Reaction Steps

A solution of 2-amino-5-methylbenzoic acid (172 mg, 1.10 mmol) in THF (1 ml) was treated with 4-phenoxyphenyl isocyanate (241 mg, 1.10 mmol). The mixture was kept at room temperature for 24 h, during which time the solvent was allowed to evaporate to leave a pale brown solid. This was dissolved in DMF (5 ml) and added to a suspension of PS-EDC (0.8 mmol g−1, 2.8 g) in DMF (20 ml). The resulting mixture was agitated at room temperature for 18 h, after which the resin was filtered off and washed with DMF (2×5 ml). The filtrate and washings were combined and evaporated under reduced pressure. Flash column chromatography over silica (20% ethyl acetate in hexane as eluent) afforded the required compound as an off-white solid (153 mg, 40%); δH (400 MHz, DMSO-d6) 2.36 (3H, s, CH3), 6.96 (2H, d, J8, Ph), 7.04 (1H, d, J8, Ph), 7.09 (1H, t, J8, Ph), 7.26 (1H, d, J8, Ph), 7.34-7.38 (2H, m, Ph), 7.55-7.56 (1H, m, Ph), 7.76-7.78 (4H, m, Ph); m/z (ES+) 345 (MH+).

Provenance & Evidence