反应详情

28.6 g of 2,4-dibromobutyric acid methyl ester are added dropwise at room temperature to a mixture of 17.8 g of 5-amino-2-chloro-4-fluoro-thiophenol and 15.2 g of potassium carbonate in 160 ml of methyl ethyl ketone (exothermic reaction). The reaction mixture is then heated under reflux for 2 hours. After cooling of the reaction mixture, the inorganic portion of the mixture is filtered off and washed with methyl ethyl ketone. Concentration of the organic solution by evaporation and chromatographic purification of the residue by means of silica gel chromatography yield 25.5 g of 2-(5-amino-2-chloro-4-fluoro-phenylthio)-4-bromobutyric acid methyl ester having a melting point of from +97° to +99° C.

1. temperatureThe reaction mixture is then heated
2. temperatureunder reflux for 2 hours
3. temperatureAfter cooling of the reaction mixture
4. filtrationthe inorganic portion of the mixture is filtered off
5. washwashed with methyl ethyl ketone
6. customConcentration of the organic solution by evaporation and chromatographic purification of the residue by means of silica gel chromatography yield 25.5 g of 2-(5-amino-2-chloro-4-fluoro-phenylthio)-4-bromobutyric acid methyl ester having a melting point of from +97° to +99° C.