反应详情

Crude 3-(1,1-dimethyldecyl)-4-methoxybenzoic acid, prepared starting with 1.6 g (5 mmoles) of 3-(1,1-dimethyldecyl)-4-methoxybenzoic acid, described in Example 11 of European Patent No. 0.232.199 is dissolved in 20 ml of dichloromethane. The solution is slowly added to a mixture of 771 mg (5 mmoles) of 4-mercaptobenzoic acid and 8 ml of pyridine. The reaction mixture is stirred at ambient temperature for 8 hours, evaporated to dryness, taken up in water, acidified to pH 5 with 1N HCl and extracted o with ethyl ether (500 ml). The organic phase is decanted, washed with water, dried over magnesium sulfate and evaporated to dryness. The resulting residue is purified by chromatography on a silica column, by using as the eluant ethyl ether. 1.92 g (84% yield) of 4-[3-(1,1-dimethyldecyl)-4-methoxybenzoylthio] benzoic acid whose melting point is 186°-187° C. are obtained.

1. customevaporated to dryness
2. extractionextracted o with ethyl ether (500 ml)
3. customThe organic phase is decanted
4. washwashed with water
5. dry with materialdried over magnesium sulfate
6. customevaporated to dryness
7. customThe resulting residue is purified by chromatography on a silica column