Iodine → 1-(5-Bromopyridin-3-yl)cyclopentanol

Participants

Reaction Conditions

Reaction Steps

A few drops of 1,4-dibromobutane and 25 ml of tetrahydrofuran are added to a round-bottomed flask containing 2.25 g of magnesium chips (92.6 mmol) and an iodine crystal. The mixture is heated at 65° C. until decolorization is obtained and then a solution of 1,4-dibromobutane (10 g, 46.3 mmol) in 50 ml of tetrahydrofuran is added dropwise. The reaction mixture is heated at 65° C. for 4 hours and then cooled to 0° C. A solution of ethyl 2-bromonicotinate (10 g, 46.3 mmol) in 60 ml of tetrahydrofuran is then added. The reaction mixture is cooled to room temperature and stirred for 16 hours. The reaction mixture is slowly poured at 0° C. into a saturated aqueous ammonium chloride solution and then the medium is extracted with ethyl acetate. The organic phase is washed with water and then with a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue is purified by flash chromatography on silica gel (cyclohexane/ethyl acetate: 70/30). The title product (3.6 g) is obtained in the form of a white solid.

Provenance & Evidence