3-Fluorophenol → HCID 13039288, compound

Participants

Reaction Steps

To a mixture of 6.23 g of trans-1-ethoxycarbonyl-3-phenyl-4-piperidinol, 7.21 g of triphenylphosphine and 2.49 ml of m-fluorophenol in 250 ml of anhydrous benzene is added dropwise under nitrogen at 5° C. over a 90 minute period a solution of 4.79 g of diethyl azodicarboxylate in 250 ml of benzene. After the addition is complete the mixture is stirred overnight at room temperature. The solid is filtered, washed with benzene, and the filtrate is concentrated in vacuo to a gum. The gum is triturated overnight in a stoppered flask with 250 ml of hexane. The solid is filtered and washed with hexane. The filtrate is washed with 10% aqueous sodium hydroxide solution (3×75 ml), water (2×100 ml), saturated sodium chloride solution (100 ml) and dried overnight over anhydrous sodium sulfate. Filtration and concentration in vacuo affords a light yellow oil. Chromatography of the oil on 430 g of silica gel, using 2:1 (petroleum ether:ether), affords a colorless, cloudy gum. Trituration of the gum with petroleum ether yields product as a colorless crystalline solid, mp 74°-76.5° C.

Provenance & Evidence