Réaction #358386

Équation de réaction

hydrochloric acid

dimethyl-thiocarbamic acid S-{4-[2-(tert-butyl-diphenyl-silanyloxy)-ethyl]-2,6-dichloro-phenyl}ester

Dimethyl-thiocarbamic acid S-{4-[2-(tert-butyl-diphenyl-silanyloxy)-ethyl]-2,6-dichloro-phenyl}ester

potassium hydroxide

→

2-(3,5-dichloro-4-mercapto-phenyl)-ethanol

Rendement 76.2%

2-(3,5-Dichloro-4-mercapto-phenyl)-ethanol

Rendement 76.2%

Solvants

ethanol

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAt this time, the reaction was poured onto water (200 mL)
2. 2
   Extractionextracted into methylene chloride (3×100 mL)
3. 3
   LavageThe organics were washed with water (1×100 mL)
4. 4
   Séchagea saturated aqueous sodium chloride solution (1×100 mL), dried with magnesium sulfate
5. 5
   Filtrationfiltered
6. 6
   Concentrationconcentrated under vacuum

Mode opératoire

A solution of dimethyl-thiocarbamic acid S-{4-[2-(tert-butyl-diphenyl-silanyloxy)-ethyl]-2,6-dichloro-phenyl}ester (72) (2.0 g, 3.76 mmol) in ethanol (6.0 mL) was treated with a 3N aqueous potassium hydroxide solution (4.4 mL, 13.2 mmol). The reaction was then heated to 95° C. for 18 h. At this time, the reaction was poured onto water (200 mL), acidified to pH=2 with a 3N aqueous hydrochloric acid solution, and then extracted into methylene chloride (3×100 mL). The organics were washed with water (1×100 mL) and a saturated aqueous sodium chloride solution (1×100 mL), dried with magnesium sulfate, filtered, and concentrated under vacuum. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 80:20 petroleum ether/ethyl acetate) afforded 2-(3,5-dichloro-4-mercapto-phenyl)-ethanol (73) (639 mg, 76%) as a white solid; EI(+)-HRMS m/e calcd for C8H8Cl2OS (M+) 221.9673, found 221.9672. Exact Mass=221.9673; Molecular Weight=223.12

Source