Water → Dichloro-1,2-thiazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Into a 500-mL round-bottom flask, was placed dichloro-1,2-thiazole-4-carbonitrile (36 g, 201.09 mmol, 1.00 equiv), Conc. sulfuric acid (100 mL). The resulting solution was stirred for 2 h at 100° C. in an oil bath. This was followed by the addition of a solution of NaNO2 (15 g, 217.39 mmol, 1.08 equiv) in water (100 mL) dropwise with stirring at 0° C. The resulting solution was allowed to react, with stirring, for overnight while the temperature was maintained at 50° C. in an oil bath. The resulting solution was diluted with 500 mL of water. The resulting solution was extracted with 5×500 mL of ethyl acetate and the organic layers combined. The resulting mixture was washed with 1×500 mL of brine. The mixture was dried over anhydrous sodium sulfate and concentrated under vacuum. This resulted in 30 g (75%) of dichloro-1,2-thiazole-4-carboxylic acid as red oil. Mass spectrum (ESI, m/z): Calcd. for C4HCl2NO2S, 197.1 (M+H). found 197.1.

Provenance & Evidence