4-Fluorobenzonitrile → cis-4-(4-Cyanophenoxy)-1-methyl-3-phenylpiperidine

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Reaction Conditions

Reaction Steps

A mixture of 0.31 g of sodium hydride, 2.48 g of cis-1-methyl-3-phenyl-4-piperidinol of Example 22 and 20 ml of dry DMF is slowly heated to 80° C. When hydrogen evolution is no longer observed, the mixture is cooled to 3° C. and a solution of 1.73 g of p-fluorobenzonitrile in 10 ml of DMF is added. The mixture is stirred for 18 hours at room temperature under nitrogen, poured into 100 ml of distilled water, and extracted with chloroform. The chloroform extracts are dried over anhydrous Na2SO4 and concentrated in vacuo to an oil containing DMF. This oil is partitioned between saturated aqueous NaCl solution and ether. The aqueous phase is extracted with ether, and the ether extracts are then washed with water and dried over anhydrous Na2SO4. Concentration in vacuo affords an oil which crystallizes while under high vacuum. This material is chromatographed on silica gel, using 25% methanol/acetone solution to obtain cis-4-(4-cyanophenoxy)-1-methyl-3-phenylpiperidine, m.p. s 138°, 139°-141° C.

Provenance & Evidence