反应详情

A solution of ethyl 4-(4-oxobutyl)benzoate (5.5 g., 0.025 mole) and 1-(2-aminoethyl)cyclohexanol (3.7 g., 0.026 mole) in toluene (40 ml.) is boiled in an open flask for 5 minutes to remove the formed water as the azeotrope. 2-Mercapto-2-methylpropionic acid (3.3 g., 0.0275 mole) is added and the solution is boiled under a Dean-Stark water separator for 5 hours. The solution is then cooled, washed with 2 N hydrochloric acid and water, and dried over sodium sulfate. The solvent is removed at reduced pressure. The residue is chromatographed on 165 g. of silica gel with 2% methanol in chloroform as the eluent. There is obtained 4.6 g. of the title ester as a light yellow, viscous oil.

1. customto remove the formed water as the azeotrope
2. temperatureThe solution is then cooled
3. washwashed with 2 N hydrochloric acid and water
4. dry with materialdried over sodium sulfate
5. customThe solvent is removed at reduced pressure
6. customThe residue is chromatographed on 165 g
7. customThere is obtained 4.6 g