反应详情

A mixture of glycine ethylester hydrochloride (15 mmol), 2-acetylamino-thiazole-5-sulfonyl chloride (12 mmol) (prepared as described in J. Am. Chem. Soc 69, 2063, 1947), DIPEA (35 mmol) in DCM (50 mL) was stirred at room temperature over night. Addition of water and 1N HCl to pH 2 resulted in precipitation. The precipitate was isolated by filtration, washed with water and dried to give (2-acetylamino-thiazole-5-sulfonylamino)-acetic acid ethyl ester (64%) as crystals. This was suspended in EtOH (15 mL) and added 4N HCl in dioxane (15 mL) and heated for 4 h at 80° C. and then cooled to room temperature. Addition of aqueous NaHCO3 to neutral pH. The organic phase was isolated and the aqueous phase was extracted with CH2Cl2, and the combined organic phases were dried and concentrated in vacuo to give (2-amino-thiazole-5-sulfonylamino)-acetic acid ethyl ester (80%) as colourless crystals.

1. customresulted in precipitation
2. customThe precipitate was isolated by filtration
3. washwashed with water
4. customdried