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

Participants

Reaction Steps

To a suspension of Mg turnings (3 g, 0.123 mol) in THF (40 ml) was added a small amount of solid I2 (20 mg). The mixture was heated to reflux under nitrogen. To the mixture was then added a small reaction-initiating amount (5 ml) of a solution of 19.6 g of 2-bromothiophene in 40 ml of THF. After the iodine color disappeared, the remainder of the 2-bromothiophene solution was added dropwise at a rate to maintainin reflux. After the addition, the mixture was heated under reflux for 2 hours, then was cooled to room temperature. To this mixture was added 0.3 g of CuCl catalyst followed by the dropwise addition of 4-fluorobenzyl chloride (14.4 g), again at a rate to maintain reflux. The mixture was stirred at room temperature for 2 h. After this period, saturated NH4Cl solution (100 ml) was added and the mixture was stirred for 30 min., the organic layer was separated and washed with 10% sodium thiosulfate solution (50 ml), followed by distilled water (100 ml). The organic layer was then dried over MgSO4 and concentrated to give 19 g of 2-(4-fluorobenzyl)thiophene as an oil. Purification was achieved by vacuum distillation (110° C., 5 mmHg).

Provenance & Evidence