Potassium Carbonate → Cyclopyrimorate

To 6.50 g (23.5 mmol) of 6-chloro-3-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinol were added 39 g of butyl acetate and 3.57 g (25.9 mmol) of potassium carbonate, and the resultant mixture was stirred at 50° C. To the mixture was added dropwise 3.87 g (25.9 mmol) of morpholinecarbonyl chloride over one hour. The reaction mixture was subjected to reaction at 50° C. for 6 hours. After completion of the reaction, the resultant opaque mixture was subjected to filtration, and washed with butyl acetate, and then the resultant organic phase was quantitatively determined by an HPLC internal standard analysis method, which showed that 9.09 g of 6-chloro-3-(2-cyclopropyl-6-methylphenoxy)-4-pyridazinyl morpholine-4-carboxylate (yield: 99%) was obtained.