3-Methylpyridine → Nicotinic Acid

Participants

Reaction Steps

In the presence of an oxidation catalyst (N-acetoxyphthalimide (NAPI)) and a metal catalyst (cobalt acetate and manganese acetate) with nicotinaldehyde as a co-oxidizing agent, β-picoline was oxidized in acetic acid solvent at 140° C. and 2 MPa with air to produce nicotinic acid. From the reaction mixture, acetic acid was removed and to a condensate was added 2-ethylhexanol. The mixture was cooling-crystallized to 25° C. at atmospheric pressure and filtrated, and the residue washed with methanol and filtrated to separate nicotinic acid. The filtrate and washing liquid were combined and the solvent was removed therefrom. The components in the condensed residue were analyzed, and as a result, 92 g of nicotinic acid, 160 g of 2-ethylhexanol, 1.0 g of N-acetoxyphthalimide (NAPI), 1.8 g of N-hydroxyphthalimide (NHPI), 108 g of phthalic acid (PA), 67 g of phthalimide (PI), 24 g of phthalic anhydride (APA), 11 g of total cobalt, 11.4 g of total manganese were contained.

Provenance & Evidence