1,4-Dibromobutane → 1-Benzhydryl-3-{[3-(4-bromobutoxy)phenyl]methanesulfonylmethylene}azetidine

Participants

Reaction Steps

1-Benzhydryl-3-{[3-(4-bromobutoxy)phenyl]-methanesulfonylmethylene}azetidine may be prepared in the following manner: 0.586 cm3 of 1,4-dibromobutane and 255 mg of potassium carbonate are successively added at a temperature close to 20° C., under an inert atmosphere of argon, to a solution of 500 mg of 1-benzhydryl-3-[(3-hydroxyphenyl)(methylsulfonyl)methylene]azetidine in 10 cm3 of methylethyl ketone. The reaction mixture is heated at the reflux temperature of the solvent, under an inert atomosphere of argon, for 7 hours and then left at a temperature close to 20° C. for about 4 days. The reaction mixtue is filtered on sintered glass covered with celite. The solid residue is rinsed with ethyl acetate and then the filtrate is concentrated to dryness under reduced pressure (10 kPa) at a temperature close to 40° C. The brown oil obtained is purified by chromatography at atmospheric pressure on 40 g of silica (0.063-0.200 mm) contained in a column 3 cm in diameter, eluting with a methanol-dichloromethane mixture (0.5-99.5 by volume). The fractions (10 cm3) containing only the desired product are combined and concentrated to dryness under reduced pressure (0.27 kPa) at 40° C. for 2 hours, 408.4 mg of 1-benzhydryl-3-{[3-(4-bromobutoxy)phenyl]methanesulfonylmethylene}azetidine are thus obtained in the form of a brown foam.

Provenance & Evidence