Sodium Carbonate → (-)-5-[2-(1-methyl-1H-pyrazol-4-yl)pyrid-5-yl]-1-azabicyclo[3.2.1]octane

Participants

Reaction Conditions

Reaction Steps

0.162 g (0.78 mmol) of 1-methyl-4-pyrazolylboronic acid, 0.160 g (0.6 mmol) of (−)-5-(2-bromopyrid-5-yl)-1-azabicyclo[3.2.1]octane (obtained by reacting 5-(2-bromopyrid-5-yl)-1-azabicyclo[3.2.1]octane (−)-hydrobromide (1:1), prepared in step 1.2, with saturated aqueous sodium carbonate solution) are successively introduced into a 10 ml three-necked round-bottomed flask, as a solution in 3 ml of toluene and 0.3 ml of ethanol. 0.035 g (0.03 mmol) of tetrakis(triphenylphosphine)palladium and 0.6 ml of aqueous 2M sodium carbonate solution are then added and the mixture is heated at 105° C. for 18 hours. It is cooled to room temperature, the solvent is evaporated off under reduced pressure and the residue is taken up in 10 ml of chloroform and filtered through diatomaceous earth. The solvent is concentrated under reduced pressure and the residue is purified by chromatography on a column of silica gel, eluting with a mixture of chloroform, methanol and aqueous ammonia in 95/5/0.5 proportions. 0.15 g of (−)-5-[2-(1-methyl-1H-pyrazol-4-yl)pyrid-5-yl]-1-azabicyclo[3.2.1]octane is obtained, and is dissolved in 2 ml of isopropyl alcohol to add 0.196 ml of a 5.7N solution of hydrobromic acid in acetic acid. The crystals obtained are collected by filtration and dried under vacuum.

Provenance & Evidence