Iodine → 5-Iodo-2-methyl-thiazole-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 2-methylthiazole-4-carboxylate (11.2 g, 65.4 mmol) in acetic acid (200 mL) were added sulfuric acid (30%, 20 mL), carbontetrachloride (30 mL), iodine (33.2 g, 131 mmol) and iodic acid (11.5 g, 65.4 mmol) and the resulting reaction mixture was stirred for 19 h at 80° C. After addition of aqueous sodium thiosulfate (1 M, 500 mL) it was extracted with ethyl acetate (1000 mL). The combined organic layers were washed with aqueous sodium carbonate (saturated, 1000 mL), dried over sodium sulfate and concentrated. Purification by chromatography (SiO2, heptane:ethyl acetate=95:5 to 20:80) afforded the title compound (9.00 g, 37%) as a white crystalline solid. MS: m/e=298.1 [M+H]+.

Provenance & Evidence