反应详情

22.5 g of 88% potassium hydroxide are suspended in 120 ml of dimethyl sulfoxide. With stirring, 40 g of trifluoroethanol are added dropwise to this suspension. Then, also with stirring, the resultant solution is added dropwise at room temperature to a solution of 96.8 g of 2,4-difluoro-5-chloronitrobenzene in 150 ml of dimethyl sulfoxide. When the addition is complete, the reaction mixture is stirred for a further 2 hours at room temperature. The reaction mixture is then concentrated, the crude product is dissolved in methylene chloride, and the resultant solution is washed with water and dried. Finally, the solvent is distilled off. Purification is effected by chromatography through a column of silica gel with a 10:1 mixture of hexane and ether as eluant. The solvent is distilled off, affording the title compound of the formula ##STR10## in the form of yellow crystals; m.p.: 54°-55° C.

1. stirringThen, also with stirring
2. additionWhen the addition
3. stirringthe reaction mixture is stirred for a further 2 hours at room temperature
4. concentrationThe reaction mixture is then concentrated
5. dissolutionthe crude product is dissolved in methylene chloride
6. washthe resultant solution is washed with water
7. customdried
8. distillationFinally, the solvent is distilled off
9. customPurification
10. additionis effected by chromatography through a column of silica gel with a 10:1 mixture of hexane and ether as eluant
11. distillationThe solvent is distilled off