Sulfuric Acid → 2,4,5-Trifluorobenzenesulfinic acid

2,4,5-Trifluoro-benzenesulfonyl chloride ([220227-21-4], 2.5 g) was added portionwise onto a solution of sodium sulfite (10.3 g) in 50 mL of water. The reaction mixture was kept under basic conditions by the addition of the proper amount of 20% NaOH and was stirred at room temperature for 1 hour. Methanol was added to the reaction mixture, and the reaction mixture was stirred at room temperature for another hour. After such time, the reaction mixture was cooled down with an ice bath and was then acidified by the addition of 20% H2SO4 solution until reaching pH 2. The aqueous solution was then extracted several times with diethyl ether and ethyl acetate. The aqueous solution was further extracted with ethyl acetate using a Kutscher-Steudel apparatus (continuous extraction). The combined organic phases were dried (sodium sulfate) an concentrated in vacuo to yield the title compound as a white solid (2.1 g).

1. stirringthe reaction mixture was stirred at room temperature for another hour
2. temperatureAfter such time, the reaction mixture was cooled down with an ice bath
3. extractionThe aqueous solution was then extracted several times with diethyl ether and ethyl acetate
4. extractionThe aqueous solution was further extracted with ethyl acetate using
5. extractiona Kutscher-Steudel apparatus (continuous extraction)
6. dry with materialThe combined organic phases were dried (sodium sulfate)
7. concentrationan concentrated in vacuo

ORD record

ord-362a4ea739c74b83b6571fd92bc8722b

Source dataset

uspto-grants-2008_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07319099B2