Pyridine → 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorophenyl chlorosulphate

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Reaction Steps

A solution of 10.16 g of 3-(4-chloro-2-fluoro-5 -hydroxyphenyl)-1-methyl-6 -trifluoromethyl-2,4 (1H,3H)-pyrimidinedione and 20.20 g of sulphuryl chloride in 100 ml of methylene chloride is treated with a solution of 3.56 g of pyridine in 10 ml of methylene chloride while stirring and cooling during 5 minutes. The temperature rises to 20° C. The reaction mixture is stirred at 20°-25° C. for 15 minutes, subsequently poured on to ice and stirred vigorously. The organic phase is washed throughly with water, dried over anhydrous sodium sulphate and evaporated to dryness under reduced pressure. The residue is recrystallized from diethyl ether/n-hexane. There is obtained 2-chloro-5-[3,6-dihydro-2,6-dioxo-3-methyl-4-trifluoromethyl-1(2H)-pyrimidinyl]-4-fluorophenyl chlorosulphate m.p. 133°-135° C.

Provenance & Evidence