Diisopropylamine → 3-Bromopyridine-4-carboxaldehyde

Participants

Reaction Conditions

Reaction Steps

A solution of di-isopropylamine (3.44 g, 34.1 mmol) was cooled to -78° C. and treated with n-butyl lithium 1.6 M, 34.1 mmol). A solution of 3-bromopyridine (4.71 g, 30 mmol) in THF (5 ml) was added dropwise trying to keep the temperature below -70° C. The reaction was very exothermic, a solid precipitated and THF (2 ml) was added to improve stirring. The temperature rose to -45° C., and after cooling to -60° C. the remaining 3-bromo pyridine was added. DMF (2.49 g) in THF (15 ml) was added and the reaction stirred at -65° C. for 30 minutes. Water was added to quench the reaction and the reaction allowed to warm to ambient temperature. The reaction was partitioned between ethyl acetate/water and the aqueous layer extracted with ethyl acetate. The organic layers were combined, dried (MgSO4) and evaporated and the residue was subjected to chromatography (eluting with diethyl ether/hexane) to give 3-bromo-4-pyridinecarbaldehyde (1.4 g, 76%).

Provenance & Evidence