Hydrochloric Acid → 2-Chloro-4-fluoro-5-aminophenyl methanesulfonate

A suspension of 2-chloro-4-fluoro-5-nitrophenyl methanesulfonate (27.0 g) and iron (33.5 g) in water (140 ml) was heated for reduction of the nitro group into amino group. When the temperature of the reaction mixture reached 80° C., 35% hydrochloric acid (3.2 g) was added thereto. Upon cooling to room temperature, the pH of the reaction mixture was adjusted to 9.0 with the addition of an aqueous sodium hydroxide solution. The reaction mixture was then extracted with toluene and tetrahydrofuran. The organic layer so separated was washed with water, dried over anhydrous sodium sulfate and then distilled under reduced pressure to remove the solvent, affording the titled compound (22.3 g) as a pale yellow oil which was then purified by silica gel chromatography to give colorless crystals with melting point 79°-80° C.

1. temperaturewas heated for reduction of the nitro group into amino group
2. customreached 80° C.
3. extractionThe reaction mixture was then extracted with toluene and tetrahydrofuran
4. customThe organic layer so separated
5. washwas washed with water
6. dry with materialdried over anhydrous sodium sulfate
7. distillationdistilled under reduced pressure
8. customto remove the solvent

ORD record

ord-fe01b259de49419b95da5a3a723218c8

Source dataset

uspto-grants-1988_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04752326