Yield:122307-41-9 95%

Reaction Conditions:

with phosphotungstic acid;dihydrogen peroxide in water at 85 - 87; for 5 h;Temperature;

Steps:

2.1
Step 1, the 12 parts by weight of the acidic phosphotungstic acid dissolved in water prepared for mass concentration 25% phosphotungstic acid solution;Step 2, weighing 220 parts by weight of 4 - chloro -3 - methoxy -2 - methyl pyridine, slowly added under stirring step 1 bedded phosphotungstic acid solution, stirring to complete mixing, heating in water bath temperature is raised to 87 °C, dropwise 350 parts by weight of the mass concentration is 35% hydrogen peroxide, hydrogen peroxide is accelerated-rate drop 60 parts by weight/hours; then in 85 °C lower heat insulating 5 hours, to obtain the reaction solution;Step 3, the reaction cooling to 30 °C is added after a dilute alkali solution (mass concentration 12% sodium hydroxide aqueous solution) adjusted to pH 7 - 9, then the dichloromethane extraction, water washing extract in neutral, adds anhydrously Na₂SO₄Drying, at a temperature of 35 - 45 °C, pressure 0.06 - 0.08 mpa evaporating the dichloromethane under reduced pressure, to obtain 230.2 parts by weight of the obtained 4 - chloro -3 - methoxy -2 - methyl pyridine - N - oxide; high performance liquid chromatogram of the product, the product appearance time is as shown in Figure 7, 3.740 min, according to the appearance time can be qualitative verification product; product 4 - chloro -3 - methoxy -2 - methyl pyridine - N - oxide of high purity, according to the area of the yield of the product is calculated unitary method 95%.

References:

Anhui Jin He Industrial Co., Ltd.;Chuzhou College;Xia Jiaxin;Wang Yonggui;Ge Xiutao;Geng Qingbao;Yang Zhijian CN107129466, 2017, A Location in patent:Paragraph 0026-0040

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