Thiophene → 2-[(4-Fluorophenyl)methyl]thiophene

Participants

Reaction Conditions

Reaction Steps

A solution of thiophene (12.6 g, 0.15 mol) in a mixture of anhydrous ether (230 mL) and anhydrous THF (70 mL) was treated dropwise at 0° C. with a 2.5M solution of n-butyllithium in hexane (54.0 mL, 0.134 mol). The mixture was stirred at 0° C. for 1.5 hours and then transferred by cannula into a -78° C. solution of 4-fluorobenzyl bromide (23.6 g, 0.125 mol) containing tetrakis(triphenylphosphine) palladium(0) (1.25 g) in anhydrous THF (200 mL). The reaction mixture was stirred at ambient temperature under nitrogen overnight and then quenched with saturated NH4Cl solution (100 mL) and partitioned between ether and additional NH4Cl solution. The ether layer was dried over MgSO4, concentrated in vacuo and the residue subjected to vacuum distillation to give 19.4 g (81% ) of 2-(4-fluorophenylmethyl)thiophene. b.p. 74°-83° C. at 0.6-0.7 mm of Hg.

Provenance & Evidence