反应详情

To a vigorously stirred suspension of ethyl 2-(tert-butoxycarbonylamino)thiazole-5-carboxylate (4.2 g, 15 mmol) in methanol (11 mL) was added 2 M aqueous solution of NaOH (22 mL, 44.0 mmol). The suspension was stirred at room temperature overnight. The mixture was concentrated in vacuo to remove methanol. The residual aqueous suspension was acidified with 6 N aqueous solution of HCl to pH ˜1-2. The mixture was stirred and occasionally sonicated for 1 hr. The solid was filtered, washed with water, and dried to give 2-(tert-butoxycarbonylamino)thiazole-5-carboxylic acid (3.7 g, 100% yield) as a white solid. MS found: (M+H-Boc)+=145.

1. concentrationThe mixture was concentrated in vacuo
2. customto remove methanol
3. stirringThe mixture was stirred
4. customoccasionally sonicated for 1 hr
5. filtrationThe solid was filtered
6. washwashed with water
7. customdried