Dichloromethane → 1-[(2-Bromoethyl)thio]-3,5-difluorobenzene

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Reaction Steps

A solution of 2.59 g of sodium hydroxide pellets in 27 cm3 of distilled water and then 0.27 cm3 of aliquat 336 (tricaprylylmethylammonium chloride) were added, with stirring and under an inert atmosphere, to a mixture, maintained at a temperature in the region of 23° C., of 7.5 g of 3,5-difluorothiophenol in 9.01 cm3 of 1,2-dibromoethane. After stirring for 15 minutes at a temperature in the region of 20° C., 50 cm3 of dichloromethane were added to the mixture and then, after a few minutes, the organic phase was separated by settling, washed with 25 cm3 of water and 25 cm3 of a saturated 10% sodium chloride solution, dried over magnesium sulfate, filtered, and evaporated under reduced pressure (5 kPa) at a temperature in the region of 40° C. The evaporation residue was purified by chromatography under a nitrogen pressure of 50 kPa on a column of silica gel (particle size 40-63 μm; diameter 5 cm; height 30 cm), elution was carried out with cyclohexane, and first a fraction of 500 cm3 was collected, followed by 50-cm3 fractions. Fractions 9 to 26 were combined and then concentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C. 5.9 g of 1-[(2-bromoethyl)thio]-3,5-difluorobenzene were obtained in the form of a colorless liquid. Infrared spectrum (CCl4): 3094, 1607, 1587, 1429, 1192, 1122, 988, 876, 841, and 667 cm−1.

Provenance & Evidence