1.04 g (3.0 mmol) of 2-chloro-3-(5-methoxymethylisoxazol-3-yl)-4-methylsulfonylbenzoic acid are introduced into 50 ml of dichloromethane together with 0.37 g (3.3 mmol) of cyclohexanedione and treated with 0.68 g (3.3 mmol) of dicyclohexylcarbodiimide. After stirring at room temperature for 16 hours, the precipitate is filtered off with suction and the filtrate is washed with water. After the removal of the solvent, 1.22 g (92% of theory) of 3-oxo-1-cyclohexenyl 2-chloro-3-(5-methoxymethylisoxazol-3 yl)-4-methyl-sulfonylbenzoate are obtained as a yellowish, partly crystalline oil.
