Dimethylformamide → 4-Chloropyridine-3-carbaldehyde

Participants

Reaction Steps

A solution of 4-chloropyridine (2.89 g, 25.5 mmol) in THF (15 ml) at -78° C. was added to a stirred solution of lithium di-isopropylamide prepared by addition of n-butyl lithium (10.2 ml of 2.5 M, 25.5 mmol) to a solution of di-isopropylamine (2.58 g, 25.5 mmol) in dry tetrahydrofuran at -78° C. After 2 hours a solution of DMF (2.05 g, 28.1 mmol) in THF (25 ml) at -78° C. was added. After a further 1 hour at -78° C. the reaction mixture was allowed to warm slowly to room temperature (16 hours). The resulting solution was poured into saturated brine (200 ml) and extracted with ether (3×100 ml). The combined ether extracts were washed with saturated brine and then the solvent was evaporated. Flash chromatography (eluent petrol-ether) of the resulting residue gave 4-chloro-3-pyridine carboxaldehyde (2.86 g) as a solid; melting point 53-54° C.; infrared max (nujol) 1580, 1695 cm-1 ; 1H NMR delta (CDCl3) 7.45 (1H,d), 8.70 (1H,d), 9.07 (1H,s), 10.50 (1H,s).

Provenance & Evidence