Diisopropylethylamine → 4-nitrophenyl 7-(N-(4-methoxybenzyl)-N-(thiazol-2-yl)sulfamoyl)-2H-benzo[b][1,4]oxazine-4(3H)-carboxylate

Participants

Reaction Steps

To a stirred solution of N-(4-methoxybenzyl)-N-(thiazol-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine-7-sulfonamide (INTERMEDIATE M, 0.200 g, 0.479 mmol) and Hunig's base (0.092 ml, 0.527 mmol) in DCM (2.395 ml) was added 4-nitrophenyl chloroformate (0.097 g, 0.479 mmol) (change from colorless to light yellow solution). The reaction was stirred at RT overnight, at which point starting material remained. Additional 4-nitrophenyl chloroformate (0.097 g, 0.479 mmol) was added and the reaction was stirred overnight once more until completion. After concentration in vacuo, the material was purified via MPLC (12-g Redi Sep Gold) eluting with 0-100% ethyl acetate in heptanes, to yield 4-nitrophenyl 7-(N-(4-methoxybenzyl)-N-(thiazol-2-yl)sulfamoyl)-2H-benzo[b][1,4]oxazine-4(3H)-carboxylate as a white solid. m/z (ESI) 583.0 (M+H)+.

Provenance & Evidence