Triphenylphosphine dibromide → 4-(Bromomethyl)-2-chloropyridine

A solution of 0.2 g of 2-chloro-4-(hydroxymethyl)pyridine in 2.5 ml of dichloromethane is added dropwise to a solution of 0.706 g of dibromotriphenylphosphorane in 9.5 ml of dichloromethane, under an inert atmosphere of argon at a temperature in the region of 20° C. Stirring is continued at this temperature for about 1 hour. The reaction medium is taken up in 50 ml of dichloromethane and then washed with 3×50 ml of water. The organic phase is dried over magnesium sulfate, filtered and then concentrated to dryness under reduced pressure. The residue thus obtained is purified by flash chromatography using a cartridge 20 mm in diameter packed with 10 g of 20-40 μm conditioned silica, and then eluted with a mixture (cyclohexane/ethyl acetate) (8/2) (v/v) at a flow rate of 8 ml/minute. The fractions between 8 and 24 ml are concentrated under reduced pressure. 0.1 g of 2-chloro-4-(bromomethyl)-pyridine is thus obtained.

1. washwashed with 3×50 ml of water
2. dry with materialThe organic phase is dried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated to dryness under reduced pressure
5. customThe residue thus obtained
6. customis purified by flash chromatography
7. washeluted with a mixture (cyclohexane/ethyl acetate) (8/2) (v/v) at a flow rate of 8 ml/minute
8. concentrationThe fractions between 8 and 24 ml are concentrated under reduced pressure

ORD record

ord-65b4bcf943384c91837bd9e51351c17f

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07354933B2