62019-56-1

92972-48-0

62019-56-1

General procedure for the synthesis of 2,4-dichloro-5-thiazole carboxylic acid from 2,4-dichlorothiazole-5-carboxaldehyde: To a mixed solution of 2,4-dichlorothiazole-5-carboxaldehyde (500 mg, 2.74 mmol) in tetrahydrofuran (18 ml) and water (12 ml) was added sulfonamide (346 mg, 3.56 mmol) and sodium chlorite (323 mg, 3.56 mmol) to an aqueous solution (2 ml). The reaction mixture was stirred at room temperature for 2 h. After completion of the reaction, it was diluted with ethyl acetate and washed with deionized water. The organic phase was separated and concentrated under reduced pressure to give the target product 2,4-dichloro-5-thiazolecarboxylic acid (440 mg, 88% yield) as a yellow solid.