Potassium Hydroxide → 1-(5-Amino-2-chloro-4-fluorophenylthio)-cyclopropanecarboxylic acid

Participants

Reaction Steps

A solution of 2.4 g of potassium hydroxide in 50 ml of ethanol is added dropwise while stirring at a temperature of +5° C. to a solution of 14.2 g of 2-(5-amino-2-chloro-4-fluorophenylthio)-4-chlorobutyric acid ethyl ester in 25 ml of ethanol. After stirring for 18 hours, 0.9 g of potassium hydroxide is added a further 3 times, and the reaction mixture is stirred for 6 hours each time until the reaction is complete. The reaction mixture is then concentrated, water is added and extraction is carried out 3 times with ethyl acetate. The combined organic phases are dried over sodium sulfate and then concentrated by evaporation. Recrystallisation of the residue from ethyl acetate/n-hexane yields 8.4 g of 1-(5-amino-2-chloro-4-fluoro-phenylthio)-cyclopropanecarboxylic acid having a melting point of from +266° to +267° C.

Provenance & Evidence