反应详情

A solution of 3.6 g of 1-(5-amino-2-chloro-4-fluorophenylthio)-cyclopropanecarboxylic acid and a few drops of sulfuric acid in 50 ml of methanol is heated under reflux until the starting material can no longer be detected. The methanol is then evaporated off, water and ethyl acetate are added to the residue and the organic phase is washed in succession with sodium hydrogen carbonate solution, water and saturated sodium chloride solution. Concentration and purification of the crude product by means of silica gel chromatography yield 5.7 g of 1-(5-amino-2-chloro-4-fluorophenylthio)-cyclopropanecarboxylic acid methyl ester having a melting point of from +119° to +121° C.

1. temperatureunder reflux until the starting material
2. customThe methanol is then evaporated off
3. additionwater and ethyl acetate are added to the residue
4. washthe organic phase is washed in succession with sodium hydrogen carbonate solution, water and saturated sodium chloride solution
5. concentrationConcentration and purification of the crude product by means of silica gel chromatography yield 5.7 g of 1-(5-amino-2-chloro-4-fluorophenylthio)-cyclopropanecarboxylic acid methyl ester having a melting point of from +119° to +121° C.