Methanol → 2-(4-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-(methyl(2-phenoxyethyl)amino)thiazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

The title compound 2-(4-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-(methyl(2-phenoxyethyl)amino)thiazole-4-carboxylic acid (20) was prepared by the following procedure: To ethyl 2-(4-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-(methyl(2-phenoxyethyl)amino)thiazole-4-carboxylate (20C) (0.210 g, 0.34 mmol) and KOH (0.1 g, 1.8 mmol) was added MeOH (2 mL) and water (5 mL). The reaction mixture was allowed to heat to 55° C. and stirred 24 hours. The reaction was monitored by LCMS. To the reaction mixture was added (0.1 g, 1.8 mmol). The reaction mixture was allowed to heat to 55° C. and stirred for 24 hours. The reaction mixture was cooled to rt and concentrated under reduced pressure. To the crude residue was added EtOAc and water. The layers were separated and extracted with EtOAc and the combined organic extracts were washed sequentially with water, brine, dried over MgSO4, filtered, and concentrated under reduced pressure. The crude residue was purified by reverse phase HPLC to provide 0.015 g (8%) of the desired product 2-(4-(benzo[d]thiazol-2-ylcarbamoyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-(methyl(2-phenoxyethyl) amino)thiazole-4-carboxylic acid (20): LC/MS (APCI): m/z 588.1 (M+H).

Provenance & Evidence