0.2 Gram of 2-propionyl-5-[2-(4-trifluoromethylphenylthio)ethyl]cyclohexane-1,3-dione was dissolved in 10 ml of chloroform and 0.07 g of propoxyamine hydrochloride and 0.5 ml of pyridine were added to the resulting solution which was then stirred at 50°-60° C. for 5 hours. The reaction solution was poured into water, acidified with dilute hydrochloric acid and extracted with chloroform. After removing chloroform, the residue was purified by thin layer chromatography (eluent, hexane:ethyl acetate=5:1) to obtain 0.11 g of 2-(1-propoxyaminopropylidene)-5-[2-(4-trifluoromethylphenylthio)ethyl]cyclohexane-1,3-dione.
