Triphenylphosphine → 5-(5-Chloro-2,3-dihydrobenzofuran-7-yl)-3-(1-butylpiperidin-4-yl)-1,3,4-oxadiazol-2(3H)-one

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Reaction Conditions

Reaction Steps

2.38 g (0.01 mol) of 5-(5-chloro-2,3-dihydrobenzofuran-7-yl)-1,3,4-oxadiazol-2(3H)-one, in suspension in 80 ml of tetrahydrofuran, are introduced into a 250 ml three-necked round-bottomed flask, cooled to 0° C. and placed under magnetic stirring, 1.57 g (0.01 mol) of 1-butylpiperidin-4-ol, 3.41 g (0.013 mol) of triphenylphosphine and then 2.44 g (0.014 mol) of ethyl azodicarboxylate are added and the mixture is stirred at room temperature for 3 h and then at 40° C. for 3 h. The solvent is evaporated under reduced pressure and the residue is taken up in water and extracted five times with diethyl ether. The organic phase is dried over magnesium sulphate and filtered, the solvent is evaporated under reduced pressure and the residue is purified by chromatography on a column of silica gel, elution being carried out with an 80/20 mixture of ethyl acetate and heptane. 3 g of compound are obtained. Melting point: 133.8-134° C.

Provenance & Evidence