Hydrochloric Acid → HCID 22610942, compound

Participants

Reaction Steps

A suspension of 10.2 g of a mixture of 1-(2-hydroxy-3-chloro-5-fluoropyridine-6-yl)-3-methyl-4-trifluoromethylpyrimidine-2,6-dione and 1-(2-chloro-3-hydroxy-5-fluoropyridine-6-yl)-3-methyl-4-trifluoromethylpyrimidine-2,6-dione (Example H5), 7.5 g of potassium carbonate and 0.08 g of 18-crown-6 in 180 ml of acetonitrile is treated dropwise with 4.5 ml of propargyl bromide and subsequently heated overnight at 65° C. The mixture is then concentrated by evaporation in vacuo, the residue obtained is treated with ethyl acetate/ice-water mixture and 1 N hydrochloric acid until the pH is 7, the aqueous phase is separated off and extracted with ethyl acetate, and the combined organic phases are washed with water, dried over sodium sulfate and filtered, and the filtrate is concentrated by evaporation. The residue is purified by means of silica gel chromatography (eluent: n-hexane/ethyl acetate 8/2). This gives the desired isomers 1-(2-propargyloxy-3-chloro-5-fluoropyridine-6-yl)-3-methyl-4-trifluoromethylpyrimidine-2,6-dione, m.p. 121-122° C. (compd.no.1.022), 1-(2-chloro-3-propargyloxy-5-fluoropyridine-6-yl)-3-methyl-4-trifluoromethyl-pyrimidine-2,6-dione, m.p, 69-71° C. and 1-(1-propargyloxy-3-chloro-5-fluoro-2-pyridon-6-yl)-3-methyl-4-trifluoromethylpyrimidine-2,6-dione, m.p. 223-224° C.

Provenance & Evidence