Potassium Hydroxide → 3-[[2-{1-(4-Fluorobenzyl)piperidin-4-yl}ethyl]carbamoyl]-5-(4-cyanophenyl)-1,2,4-oxadiazole fumarate

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Reaction Steps

To a mixture of 3-[{2-(piperidin-4-yl)ethyl}carbamoyl]-5-(4-cyanophenyl)-1,2,4-oxadiazole hydrochloride (0.7 g), 4-fluorobenzaldehyde (0.24 g) and molecular sieves 4A (1.0 g) in methanol (7 ml) was added 1M solution of potassium hydroxide in methanol (1.93 ml). After stirring for 5 hours at ambient temperature, sodium borohydride (73 mg) was added to the mixture under ice cooling. The mixture was stirred for 20 minutes and evaporated in vacuo. The residue was dissolved in ethyl acetate and washed with water, brine, dried over magnesium sulfate and evaporated in vacuo to give a residue containing 3-[[2-{1-(4-fluorobenzyl)piperidin-4-yl}ethyl]carbamoyl]-5-(4-cyanophenyl)-1,2,4-oxadiazole. The residue and fumaric acid (0.11 g) were dissolved in hot ethanol (10 ml) and recrystallized to afford 3-[[2-{1-(4-fluorobenzyl)piperidin-4-yl}ethyl]carbamoyl]-5-(4-cyanophenyl)-1,2,4-oxadiazole fumarate (0.50 g).

Provenance & Evidence