反应详情

To a solution of tert-butyl 5-(N-(2-morpholinoethyl)-methylsulfonamido)-thiophene-2-carboxylate (Int. 58) (1.3 g, 3.33 mmol) in DCM (50 ml), TFA (2.56 ml, 33.3 mmol) was added drop-wise at 0° C. and then the brown solution was stirred at RT overnight. Additional TFA (7.69 ml, 99.9 mmol) was added in two portions over 4 hours, cooling to 0° C. and stirring at RT. The volatiles were removed under vacuum to afford 5-(N-(2-morpholinoethyl)methylsulfonamido)thiophene-2-carboxylic acid 2,2,2-trifluoroacetic acid salt (Int. 59) (1.436 g, 3.21 mmol, MS/ESI+335.0 [MH]+).

1. temperaturecooling to 0° C.
2. stirringstirring at RT
3. customThe volatiles were removed under vacuum