Carbon Dioxide → 3,5-Dimethoxyisonicotinic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 3,5-dimethoxypyridine (600 mg, 4.3 mmol) (prepared according to the method of Testaferri, L. et al Tetrahedron, 1985, 41, 1373) in THF (2.6 ml) was added to a solution of LDA [generated from n-BuLi (1.9 ml, 2.5 M in hexane, 4.73 mmol) and diisopropylamine (0.6 ml, 5.16 mmol)] in THF (2.6 ml) at −78° C. under nitrogen. The reaction mixture was stirred for 30 minutes at −78° C., transferred via cannula to a suspension of crushed solid CO2 (30 g) in toluene (100 ml) under vigorous stirring and warmed to room temperature. The reaction is quenched by addition of water (20 ml) to and 1M NaOH (10 ml) and the aqueous layer separated, acidified to pH 4 with glacial acetic acid and extracted with 10% MeOH in dichloromethane (3×50 ml). The combined organic layers were dried (MgSO4) and the solvent removed under vacuum to give the title compound (502 mg, 63%) as a white solid.

Provenance & Evidence