N-bromobutanimide → HCID 21255187, compound

Participants

Reaction Steps

2.42 g of N-bromosuccinimide are added with stirring to a solution of 3.5 g of 3-(2-chloro-3-pyridyl)-5,6,7,8-tetrahydroindolizine-1-carbonitrile in 50 cm3 of 1,2-dichloroethane. The mixture is refluxed for 20 hours. After cooling, the reaction mixture is concentrated at reduced pressure (2.7 kPa) at a temperature close to 60° C. The residue is taken up with 100 cm3 of ethyl acetate and washed 3 times with 70 cm3 of an aqueous solution of sodium bicarbonate at a concentration of 5%. The organic extracts are combined and dried over anhydrous magnesium sulphate, filtered and concentrated to dryness at reduced pressure (2.7 kPa) at a temperature close to 50° C. A mixture of products is thus obtained, which is chromatographed on a column of 1.8 cm diameter containing 90 g of silica (0.04-0.0063). Elution is carried out with dichloromethane at a total pressure of 1.5 bar and with 20-cm3 fractions being collected. The homogeneous fractions are combined and concentrated at reduced pressure (2.7 kPa) at a temperature close to 60° C. 2.79 g of 2-bromo-3-(3-pyridyl)-5,6,7,8-tetrahydroindolizine-1-carbonitrile are thus obtained in the form of white crystals melting at 188° C.

Provenance & Evidence