5-Methylnicotinic acid

Solid

5-Methylnicotinic acid is an important raw material and intermediate used in organic synthesis, pharmaceuticals and agrochemicals.

5-Methylnicotinic acid can be prepared by a one-step reaction under the condition of aqueous solvent, using 3,5-dimethylpyridine as the starting material and potassium permanganate as the oxidising agent, and reacted under mild conditions. The specific preparation method is as follows:
A, to 1200L running water is added in 2000L enamel reaction stills, then squeeze into 3,5- lutidines 120kg, stir, Between 25-35°C of temperature control, and 300kg potassium permanganate is added with 4.5h, be then incubated 30°C of reaction 16h；
B, filter core filter by-product manganese dioxide, and filtrate adjusts pH0.5 with concentrated hydrochloric acid；
C, centrifugation filter by-product 3, and 5- pyridinedicarboxylic acids, filtrate continuation adjusts PH3.0, crude product is collected by centrifugation with concentrated hydrochloric acid；
D, drying, crude product 1200L ethanol are heated to 80°C of dissolvings, heat filtering, and filtrate is cooled to 0-5°C of stirring 2h, from The heart, in drying 8.5h at 65°C, you can.The purity of final product is 99.5%.

[1] Patent: US2009/54395, 2009, A1. Location in patent: Page/Page column 42
[2] Patent: EP1193265, 2002, A2. Location in patent: Page 72
[3] Journal of Medicinal Chemistry, 1994, vol. 37, # 17, p. 2697 - 2703
[4] Journal of Chemical Research, Miniprint, 1987, # 9, p. 2360 - 2384