Hydrochloric Acid → Ethyl 2-chloro-1,3-thiazole-5-carboxylate

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Reaction Steps

To a solution of tert-butyl nitrite (9.3 g, 90 mmol) and cupric chloride (9.7 g, 72 mmol) in 150 mL of acetonitrile at 65° C. was added portionwise ethyl 2-aminothiazole-5-carboxylate (10.3 g, 60 mmol) (prepared by the method of Dann, O. Chem Ber 76 419 (1943)) resulting in vigorous gas evolution. After the addition was complete, the solution was stirred until gas evolution ceased (30 minutes). The solution was cooled and poured into 250 mL of cold 20% v/v aqueous HCl. The aqueous solution was extracted 3 times with 200 mL of EtOAc. The organics were combined, washed once with 100 mL of 20% aqueous HCl and 2 times with 100 mL saturated brine and dried over magnesium sulfate. Concentration in vacuo gave 11.1 g (97% yield) of a brown oil which required no purification.

Provenance & Evidence