Potassium Carbonate → 4-allyl-2-{4-[4-(2-methoxyphenyl)piperazin-1-yl]butyl}-5-(3-pyridyl)-1,2,4-triazol-3(2H,4H)-one

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Reaction Conditions

Reaction Steps

A mixture of 4-allyl-2-(4-chlorobutyl)-5-(3-pyridyl)-1,2,4-triazol-3(2H,4H)-one (3 g), 1-(2-methoxyphenyl)piperazine monohydrochloride (2.3 g), potassium carbonate (2.76 g), potassium iodide (10 mg) and toluene (100 ml) was stirred at 90-95° C. under nitrogen for 85 hours. During this time, three further portions of 1-(2-methoxyphenyl)piperazine monohydrochloride (3×1.92 g) were added at 17 hourly intervals. The solvent was removed in vacuo, the residue was diluted with water (100 ml), and the product was extracted into ethyl acetate (3×50 ml). The extracts were dried (MgSO4) and the solvent removed in vacuo to leave an oil which was purified by flash chromatography over silica using a 1:1 mixture of ether and methanol as eluant. Appropriate fractions were combined and the solvents removed in vacuo. The residue was triturated with ether, undissolved solid was removed by filtration, and the solvent was removed in vacuo. The residue was triturated with petroleum ether (b.p. 40-60° C.) and the resulting solid was collected by filtration and dried in vacuo at ambient temperature to give 4-allyl-2-{4-[4-(2-methoxyphenyl)piperazin-1-yl]butyl}-5-(3-pyridyl)-1,2,4-triazol-3(2H,4H)-one as an off-white solid (1 g), m.p. 71-75° C.

Provenance & Evidence