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

Temperature

100 °C

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.

1. customInto a 500-mL round-bottom flask, was placed
2. stirringwith stirring at 0° C
3. customto react
4. stirringwith stirring, for overnight while the temperature
5. temperaturewas maintained at 50° C. in an oil bath
6. extractionThe resulting solution was extracted with 5×500 mL of ethyl acetate
7. washThe resulting mixture was washed with 1×500 mL of brine
8. dry with materialThe mixture was dried over anhydrous sodium sulfate
9. concentrationconcentrated under vacuum
10. customThis resulted in 30 g (75%) of dichloro-1,2-thiazole-4-carboxylic acid as red oil

ORD record

ord-7c2e1ef7ef934319a93305019cd9ee81

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09067898B1