反应详情

To a solution of 4-(1-hydroxy-3-methyl-butyl)-benzoic acid methyl ester (1240 mg, 5.59 mmol) in toluene (10 mL) is added 1,1′-(azodicarbonyl)dipiperidine (ADDP, 2114 mg, 8.38 mmol) at 0° C., followed by the additions of tributylphosphine (2.09 mL, 8.38 mmol) and 4-bromo-thiophenol (1267 mg, 6.7 mmol). The reaction mixture is warmed up to room temperature and stirred overnight. The mixture is loaded on silica gel, eluted with hexanes with a gradient from 0% of ethyl acetate to 50% of ethyl acetate giving 4-[1-(4-bromo-phenylsulfanyl)-3-methyl-butyl]-benzoic acid methyl ester. 393 mg of the ester product is taken into ethanol (2 mL), treated with sodium hydroxide (5N aqueous, 1 mL) for 3 h at room temperature. The mixture is concentrated, diluted with ethyl acetate, acidified with 5 N HCl (1.1 mL), extracted with ethyl acetate. The organic layers are dried and concentrated giving 4-[1-(4-bromo-phenylsulfanyl)-3-methyl-butyl]-benzoic acid (379 mg).

1. concentrationThe mixture is concentrated
2. additiondiluted with ethyl acetate
3. extractionextracted with ethyl acetate
4. customThe organic layers are dried
5. concentrationconcentrated