Hydrochloric Acid → 4-tert-Butyl-1,3-thiazole-2-carboxylic acid

Participants

Reaction Steps

A solution of ethyl thiooxamate (0.75 g, 5.6 mol) and 1-bromopinacolone (1.0 g, 5.6 mol) in ethanol was heated to reflux for 2 h. The solvent was removed in vacuo and the residue dissolved in CH2Cl2 and washed with water and brine, concentrated and the residue chromatographed on silica gel (10% Ethyl acetate/hexane) to give 0.8 g of ethyl 4-tert-butylthiazole-2-carboxylate as an oil. The ester was dissolved in methanol (5 ml) and treated with 1N NaOH (30 ml) and stirred overnight at room temperature. The solution was acidified with 1N HCl and extracted into CH2Cl2 and washed with water. The solvent was removed under vacuum to give 0.55 g of 4-tert-butylthiazole-2-carboxylic acid as a off-white solid. MS found: (M+H)+=186.24

Provenance & Evidence