Dimethyl Sulfate → 2,4(1H,3H)-Pyrimidinedione, 3-(4-chloro-2-fluoro-5-(1-methylethoxy)phenyl)-1,6-dimethyl-

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Reaction Steps

A solution of 9.00 g of ethyl 3-[3-(4-chloro-2-fluoro-5-isopropoxyphenyl)ureido]-crotonate in 100 ml of anhydrous dimethylformamide is added dropwise at room temperature while stirring to a solution of 1.10 g of a 55% sodium hydride dispersion in 100 ml of isopropanol/dimethylformamide (1:1) and stirred for 1 hour. The reaction mixture is subsequently treated with 4.70 g of dimethYl sulphate and stirred at room temperature for 2 hours. The solvent is largely distilled off under reduced pressure and the residue is poured into 500 ml of water and extracted twice with 200 ml of ethyl acetate each time. The organic phases are washed 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 3-(4-chloro-2-fluoro-5-isopropoxyphenyl)-1,6 -dimethyl-2,4(1H,3H)-pyrimidinedione, m.p. 149°-151° C.

Provenance & Evidence