Hydrochloric Acid → HCID 19864569, compound

Participants

Reaction Steps

To a solution of 4-phenylnicotinic acid N-oxide (8.4 g, 0.04 mol), sodium cyanide (6.45 g, 0.13 mol) and diethylamine (26.2 ml, 0.19 mol) in absolute dimethylformamide (200 ml), chlorotrimethylsilane (23.8 ml, 0.19 mol) is added. The reaction mixture is then heated for 26 h at 100°-110°. After cooling, the solution is poured into 200 ml of water and the pH is adjusted to pH 4 by the addition of concentrated HCl. The mixture is extracted with ethyl acetate and the extracts are concentrated. The dark residue is dissolved in 150 ml of ethyl acetate and extracted with a saturated solution of sodium hydrogen carbonate. This latter extract is acidified with concentrated HCl to pH 4 and extracted again with ethyl acetate. The combined ethyl acetate extracts are evaporated to dryness, and the residue is chromatographed in ethyl acetate/methanol (1:1) on Florisil® [magnesium silicate (30-60 mesh, Fluka, Buchs, CH)]to yield 5-carboxy-2-cyano-4-phenyl-pyridine, m.p. 270°-272°, Rf =0.6.

Provenance & Evidence