Pyridine → HCID 19745816, compound

Participants

Reaction Conditions

Reaction Steps

16.61 g of pyridine are added at 25° C. while stirring to a suspension of 25.55 g of 3-[3,4-dihydro-3-oxo-4-(2-propynyl)-2H-1,4-benzoxazin-6-yl]-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione (see Example 3) and 32.13 g of phosphorus oxychloride in 250 ml of toluene. The reaction mixture is heated to 100° C. for 6 hours, cooled to 25° C. and poured on to 500 g of ice. Subsequently, the aqueous mixture is extracted three times with 150 ml of ethyl acetate each time and the organic phase is washed neutral with water, dried over anhydrous sodium sulphate and evaporated to dryness under reduced pressure. The resinous product is purified by chromatography on a silica gel column with ethyl acetate/n-hexane (1:3) as the eluent. Finally, the product is recrystallized from diethyl ether/n-hexane. In this manner there is obtained 6-[2-chloro-6-oxo-4-trifluoromethyl-1(6H)-pyrimidinyl]-4-(2-propynyl)-2H-1,4-benzoxazin-3(4H)-one, m.p. 143°-145° C. (see Example 78).

Provenance & Evidence