Hydrochloric Acid → 7-Chloro-2,2,3,3-tetrafluoro-2,3-dihydro-5-nitrobenzothiophene

Temperature

150 °C

Under a dry argon atmosphere a stirred mixture of 18.8 g (0.047 mole) 4-(2-bromo-1,1,2,2-tetrafluoroethylthio)-3,5-dichloronitrobenzene, 14.8 g (0.23 mole) cooper powder, and 7.3 g (0.0478 mole) 2,2'-dipyridyl in 300 ml of dimethyl sulfoxide was heated at 150° C. for 15 minutes. The mixture was cooled and poured into a separatory funnel containing approximately 100 g of 2N hydrochloric acid. The aqueous mixture was extracted with three 150 ml portions of diethyl ether and the extracts were combined. The extract was washed in succession with two 100 ml portions of 2N hydrochloric acid, two 100 ml portions of a saturated aqueous sodium chloride solution, two 100 ml portions of 2N sodium hydroxide, and 100 ml of 2N hydrochloric acid. The washed organic solution was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to leave an oil. This oil was subjected to column chromatography on silica gel, elution with n-heptane:toluene (90:10), to provide a solid after evaporation of the appropriate fractions. This solid was recrystallized from n-heptane to yield 7.5 g 7-chloro-2,2,3,3-tetrafluoro-2,3-dihydro-5-nitrobenzothiophene (mp 61.5°-62° C.).

1. temperatureThe mixture was cooled
2. additionpoured into a separatory funnel
3. extractionThe aqueous mixture was extracted with three 150 ml portions of diethyl ether
4. washThe extract was washed in succession with two 100 ml portions of 2N hydrochloric acid, two 100 ml portions of a saturated aqueous sodium chloride solution, two 100 ml portions of 2N sodium hydroxide, and 100 ml of 2N hydrochloric acid
5. dry with materialThe washed organic solution was dried over anhydrous magnesium sulfate
6. filtrationfiltered
7. customThe filtrate was evaporated under reduced pressure
8. customto leave an oil
9. washThis oil was subjected to column chromatography on silica gel, elution with n-heptane:toluene (90:10)
10. customto provide a solid
11. customafter evaporation of the appropriate fractions
12. customThis solid was recrystallized from n-heptane

ORD record

ord-6b9dac5092e54acd89bdeca314b3601c

Source dataset

uspto-grants-1987_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04636523