4-Nitrophenyl benzo[d]thiazol-2-ylcarbamate → 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

Participants

Reaction Conditions

Reaction Steps

To ethyl 2-(3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-(methyl(2-phenoxyethyl)amino)thiazole-4-carboxylate (20B) (0.150 g, 0.34 mmol) and 4-nitrophenyl benzo[d]thiazol-2-ylcarbamate (19) (0.349 g, 0.11 mmol) was added acetonitrile (10 mL). The reaction mixture was allowed to heat to 85° C. and stirred for 8 hours. Then the reaction mixture was allowed to heat at 70° C. and stirred overnight. The reaction mixture was allowed to cool to rt and concentrated under reduced pressure. To the concentrate was added EtOAc and water and filtered. The layers of the filtrate were separated and extracted with EtOAc. The combined organic extracts were washed sequentially with water, brine, dried over MgSO4, filtered, and concentrated under reduced pressure to provide 0.21 g (quantitative) 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): LC/MS (APCI): m/z 616.3 (M+H).

Provenance & Evidence