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

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Reaction Steps

To a 100 mL 24/40 round bottom flask was charged 3.25 g (13.8 mmol) of 2-bromo-4-thiazolecarboxylic acid ethyl ester (Helv. Chim. Acta, 1942, 25, 1073) dissolved in 20 mL of 1N sodium hydroxide. The reaction was stirred at room temperature for 3 h, cooled down in an ice bath and acidified to pH 2 with SN hydrochloric acid. The white precipitate was filtered, washed with 20 mL cold water, and dried in a vacuum oven to give 2.7 g (94%) of 2-bromo-4-thiazolecarboxylic acid. m.p. 227-229° C., Rf =0.16 (20% methanol/chloroform). 1H NMR (300 MHz, DMSO-d6) δ 8.43 (s, 1H).

Provenance & Evidence