| 摘要 |
2,3,5-trimethyl-pyridine-N-oxide 10mole solution in 1200ml conc-H2SO4 is treated with 1750ml (322M) conc-H2SO4 and 2065ml (29.84M) 65%- HNO3 solution for 1hr in 50 l reaction vessel at 90≦̸C through shaking, and then cooled to 30≦̸C for 1.5hr. 90 the solution, add 10M NaOH and adjust pH in below 40≦̸C and then add 25 l of CH2Cl2 and shake for 30min. Seperate the aqueous layer from the solution. Add 15 l of toluone to the solution and distil the solution and then add 8l of MeOH and disolve 595g of NaOH for 1.5hr after heating the solution the boiling point. 2,3,5trimethyl-4-methoxy pyridine-N- oxide 1287g, its purity of 89% is obtained by removal of solvent and inorganic salt after adjusting the pH of solution to 8 using conc- H2SO4.
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