Originator
Pemix ,Prodes ,Spain,1982
Manufacturing Process
15 kg (70.7 mols) of 3,4,5-trimethoxybenzoic acid and 65 liters of benzene were introduced into a reactor, to which mixture was added 27.4 liters of thionyl chloride. The mass was heated to 56°C to 70°C during a period of 5 hours. The excess of benzene and thionyl chloride was distilled under vacuum. The residue was kept under vacuum at 120°C to 123°C for 1 hour, to obtain a hard crystalline solid.
A solution comprising 3.24 kg (23.3 mols) of pyridine-2,6-dimethanol in 35 liters of pure pyridine was added to the residue and the mass was heated to 80°C for 2? hours. The reaction mass became brown in color. The chlorhydrate of pyridine so formed was cooled and crystallized. The resulting reaction mass was then poured into water. The precipitate obtained was filtered, repeatedly rinsed with water, and dissolved in 400 liters of methanol. The resulting solution was filtered with activated charcoal. From this filtration 50 liters of methanol were distilled at normal pressure and then crystallized. 8.35 kg (15.8 mols) of pyridine-2,6dimethanol trimethoxybenzoate were obtained, which represented a yield of 68%.
The product was a white crystalline solid which melted at 119°C to 126°C. Recrystallization in methanolone gave a product which melted at 126°C to 127°C.
