反应详情

A solution of 19.2 g (50.94 mmol) of 2,3-dibromo-3-(2,4-dichlorophenyl)propanecarboxylic acid in 130 mL of tert-butanol is combined batchwise with a total of 22.86 (203.78 mmol) of potassium tert-butoxide, so that the temperature does not exceed 40° C. Then the mixture is stirred for another 90 minutes at this temperature. The reaction mixture is poured into 2N hydrochloric acid and the precipitate is taken up in ethyl acetate. The organic phase is extracted three times with water and dried over sodium sulfate. The desiccant is filtered off and the solvent is distilled off. The residue is dried in the circulating air dryer at 80° C. Yield: 9.73 g (88.8% of theory); melting point: 168° C.-171° C.; C9H4Cl2O2 (M=215.03); Rf value: 0.5 (silica gel, dichloromethane/ethanol/glacial acetic acid (10:1:0.1)).

1. customdoes not exceed 40° C
2. extractionThe organic phase is extracted three times with water
3. dry with materialdried over sodium sulfate
4. filtrationThe desiccant is filtered off
5. distillationthe solvent is distilled off
6. customThe residue is dried in the circulating air dryer at 80° C