Benzaldehyde → HCID 22675556, compound

Participants

Reaction Conditions

Reaction Steps

A solution of sieve dried di-isopropylamine (3.24 g, 32 mM) in THF (20 ml) was cooled to −50° C. under argon and treated with n-butyl lithium (1.6 M in hexane, 19.2 ml). A suspension of 2-methyl nicotinic acid (2.0 g, 14.6 mmol) in THF (70 ml) was added slowly by syringe to the reaction mixture. A deep red/purple colour developed. The reaction was stirred for 0.75 hours allowing the temperature to rise to −40° C. The reaction was cooled to −60° C. A solution of benzaldehyde (1.86 g, 17.52 mmol) in THF (10 ml) was added dropwise keeping the temperature below −60° C. The colour of the reaction discharged to pale yellow within 15 minutes. The cooling bath was removed and the reaction was allowed to warm to 0° C. and was held at 0° C. for 18 hours. Water was added and the reaction acidified to pH 2 with 1N HCl and extracted with EtOAc. The pH of the aqueous phase was adjusted to pH 5 and re-extracted with EtOAc. The organic layers were combined, dried (56 mg) and evaporated. The resulting pale yellow oil was purified by chromatography eluting with (methanol/dichloromethane) to give 2-phenyl-8-oxopyrano[4,3-b]pyridine as a yellow oil (1.5 g)

Provenance & Evidence