反应详情

To a heterogeneous mixture of 2-(tert-butoxycarbonylamino)thiazole-5-carboxylic acid (1.0 g, 4.1 mmol), 1-hydroxybenzotriazole hydrate (0.63 g, 4.1 mmol), N,N-diisopropylethylamine (4.3 mL, 24 mmol), methylamine hydrochloride (0.83 g, 12 mmol) in anhydrous acetonitrile (20 mL), was added WSCDI (2.4 g, 12 mmol) at room temperature under a nitrogen atmosphere and stirred at room temperature overnight. The reaction mixture was concentrated in vacuo. To the residue was added saturated aqueous sodium bicarbonate solution (20 mL), ethyl acetate (6 mL), and heptane (2 mL). The solid that separates out was filtered, washed with water (2×2 mL) and diethyl ether (2×4 mL), and dried to give tert-butyl 5-(methylcarbamoyl)thiazol-2-ylcarbamate (0.77 g, 73% yield) as a white solid. MS found: (M+H)+=258; 1H NMR (400 MHz, methanol-d4) δ ppm 7.83 (s, 1H), 2.87 (s, 3H), 1.55 (s, 9H).

1. additionwas added WSCDI (2.4 g, 12 mmol) at room temperature under a nitrogen atmosphere
2. concentrationThe reaction mixture was concentrated in vacuo
3. additionTo the residue was added saturated aqueous sodium bicarbonate solution (20 mL), ethyl acetate (6 mL), and heptane (2 mL)
4. filtrationThe solid that separates out was filtered
5. washwashed with water (2×2 mL) and diethyl ether (2×4 mL)
6. customdried