Water → 2-(ethoxycarbonyl)thiazole-5-carboxylic acid

Participants

Reaction Steps

Bromopyruvic acid (22.7 g, 135.33 mmol) was added to a solution of ethyl 2-amino-2-thioxoacetate (Intermediate W, 18 g, 135.3 mmol) in dioxane (200 mL) and refluxed for 5 h. After completion the reaction mixture was poured into water (200 mL), the residue was basified with sat NaHCO3 and extracted with EtOAc (2×250 mL). The aqueous layer was acidified with 2N HCl and extracted with EtOAc (2×250 mL) The combined extracts were washed with water (250 mL), brine (250 mL), dried over anhydrous Na2SO4, filtered and evaporated to afford 2-(ethoxycarbonyl)thiazole-5-carboxylic acid (13 g crude). The crude was carried to next step without further purification.

Provenance & Evidence