Reaction #2286339

Reaction equation

hydrochloric acid

dimethyl-thiocarbamic acid S-(4-amino-2,6-dichloro-phenyl)ester

Dimethyl-thiocarbamic acid S-(4-amino-2,6-dichloro-phenyl)ester

potassium hydroxide

→

4-amino-2,6-dichloro-benzenethiol

Yield 69.0%

4-Amino-2,6-dichloro-benzenethiol

Yield 69.0%

Solvents

water

ethanol

Conditions

Workup

1. 1
   TemperatureAt this time, the reaction was cooled to 25° C.
2. 2
   Extractionwas extracted with ethyl acetate (2×250 mL)
3. 3
   DryingThe organics were dried with magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Concentrationconcentrated under vacuum to an orange solid
6. 6
   Filtrationcollected by filtration
7. 7
   Washwashed with chloroform
8. 8
   ConcentrationThe filtrate was concentrated under vacuum
9. 9
   Otherpurified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 85:15 petroleum ether/ethyl acetate)

Procedure

A solution of dimethyl-thiocarbamic acid S-(4-amino-2,6-dichloro-phenyl)ester (81) (2.0 g, 7.5 mmol) in ethanol was treated with a 3N aqueous potassium hydroxide solution. The reaction was heated to 95° C. for 2 d. At this time, the reaction was cooled to 25° C. and was then acidified to pH=2 with a 3N aqueous hydrochloric acid solution. This solution was diluted with water (500 mL) and then was extracted with ethyl acetate (2×250 mL). The organics were dried with magnesium sulfate, filtered, and concentrated under vacuum to an orange solid. The solid was slurried in chloroform, collected by filtration and washed with chloroform. The filtrate was concentrated under vacuum and purified by flash chromatography (Merck Silica gel 60, 230-400 mesh, 85:15 petroleum ether/ethyl acetate) to afford 4-amino-2,6-dichloro-benzenethiol (82) (1.0 g, 69%) as a white solid; EI(+)-HRMS m/e calcd for C6H5Cl2NS (M+) 192.9520, found 192.9519. Exact Mass=192.9520; Molecular weight=194.08

Source