Hydrochloric Acid → 3-Bromo-4-methylbenzene-1-thiol

Temperature

80 °C

A cooled (−15° C.) solution of 3-bromo-4-methylaniline (ABCR; 2.0 g) in a 6N solution of HCl in water (30 mL) was treated drop-wise with a solution of sodium nitrite (1.78 g) in water (10 mL). The reaction mixture was stirred for 30 mins. The resulting clear solution was added dropwise to a stirred solution of O-ethyl xanthic acid potassium salt (6.1 g) in water (25 mL). The mixture was then heated to 80° C. for 15 minutes. The mixture was then cooled and extracted with diethyl ether twice. The solvents were evaporated under reduced pressure to give a residue, which was treated with a solution of KOH (6.1 g) in 95% ethanol (55 mL) and heated to reflux for 10 h. The reaction mixture was diluted with water and acidified with conc. HCl to pH 3 and extracted with diethyl ether. The organic layer was washed with water, brine and concentrated under reduced pressure. The crude product was purified by column chromatography (silica gel), eluting with petroleum ether. This product obtained was triturated with hexane to give the title compound (1.5 g, 70%) as an off-white solid.

1. temperatureThe mixture was then cooled
2. extractionextracted with diethyl ether twice
3. customThe solvents were evaporated under reduced pressure
4. customto give a residue, which
5. temperatureheated
6. temperatureto reflux for 10 h
7. extractionextracted with diethyl ether
8. washThe organic layer was washed with water, brine
9. concentrationconcentrated under reduced pressure
10. customThe crude product was purified by column chromatography (silica gel)
11. washeluting with petroleum ether
12. customThis product obtained
13. customwas triturated with hexane

ORD record

ord-0c2444f0bfbe4f5eb89c74e431a47bd3

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08273769B2