Preparation method of O-methyl-N-nitroisourea

Abstract

The invention relates to the field of preparation of chemical intermediates, and concretely relates to a preparation method of O-methyl-N-nitroisourea. The preparation method of O-methyl-N-nitroisourea comprises the following steps: dissolving O-methylisourea sulfate in fuming sulfuric acid to obtain an O-methylisourea sulfate solution; dissolving fuming nitric acid into concentrated sulfuric acidto obtain a mixed acid solution; mixing the O-methylisourea sulfate solution with the mixed acid solution to obtain a reaction raw material solution, and reacting the reaction raw material solution in a micro-channel reactor at 30-60 DEG C to obtain the O-methyl-N-nitroisourea. According to the preparation method of O-methyl-N-nitroisourea provided by the invention, the reaction is easy to control, the reaction time can be shortened from several hours to tens of minutes, and the reaction yield is remarkably improved.

Description

technical field

[0001] The invention relates to the field of preparation of chemical intermediates, in particular to a preparation method of O-methyl-N-nitroisourea. Background technique

[0002] O-methyl-N-nitroisourea is an important new pesticide and pharmaceutical intermediate. As an important derivative of new low-toxicity insecticides, it is widely used in the synthesis of clothianidin, dinotefuran and other insecticides. agent. In recent years, domestic chemical safety accidents have occurred frequently, and the state strictly controls the production of dangerous traditional craft products such as nitrification. However, the domestic market has a large demand for O-methyl-N-nitroisourea, which often leads to a state of short supply.

[0003] The existing process for preparing O-methyl-N-nitroisourea is mainly to place fuming sulfuric acid in a dry reaction kettle, add O-methylisourea 1 / 2 sulfate, and wait for the material to be dissolved in the range of 0~ Add the ...

Examples

Embodiment 1

[0035] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0036] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); Fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in the concentrated sulfuric acid (concentration of sulfuric acid in the concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:1);

[0037] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is 3.8ml / min) a...

Embodiment 2

[0039] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0040] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in concentrated sulfuric acid (concentration of sulfuric acid in concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:3);

[0041] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is 3.8ml / min) and mixes...

Embodiment 3

[0043] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0044] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in concentrated sulfuric acid (concentration of sulfuric acid in concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:1);

[0045] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is mixed in 7.6ml / min),...

technical field

[0001] The invention relates to the field of preparation of chemical intermediates, in particular to a preparation method of O-methyl-N-nitroisourea. Background technique

[0002] O-methyl-N-nitroisourea is an important new pesticide and pharmaceutical intermediate. As an important derivative of new low-toxicity insecticides, it is widely used in the synthesis of clothianidin, dinotefuran and other insecticides. agent. In recent years, domestic chemical safety accidents have occurred frequently, and the state strictly controls the production of dangerous traditional craft products such as nitrification. However, the domestic market has a large demand for O-methyl-N-nitroisourea, which often leads to a state of short supply.

[0003] The existing process for preparing O-methyl-N-nitroisourea is mainly to place fuming sulfuric acid in a dry reaction kettle, add O-methylisourea 1 / 2 sulfate, and wait for the material to be dissolved in the range of 0~ Add the ...

Examples

Embodiment 1

[0035] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0036] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); Fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in the concentrated sulfuric acid (concentration of sulfuric acid in the concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:1);

[0037] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is 3.8ml / min) a...

Embodiment 2

[0039] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0040] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in concentrated sulfuric acid (concentration of sulfuric acid in concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:3);

[0041] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is 3.8ml / min) and mixes...

Embodiment 3

[0043] This embodiment provides a preparation method of O-methyl-N-nitroisourea, comprising the following steps:

[0044] 1) 123 (g) O-methylisourea 1 / 2 sulfate is dissolved in oleum (concentration of sulfur trioxide in oleum is 65wt%), obtains O-methylisourea sulfate solution ( SO in the O-methylisourea sulfate solution 3 The molar ratio of O-methylisourea sulfate is 2:1); fuming nitric acid (concentration of nitric acid in fuming nitric acid is 98wt%) is dissolved in concentrated sulfuric acid (concentration of sulfuric acid in concentrated sulfuric acid is 98wt%) , to obtain the mixed acid solution (the HNO in the mixed acid solution 3 and H 2 SO 4 The molar ratio is 1:1);

[0045] 2) The O-methylisourea sulfate solution and the mixed acid solution are respectively fed into the micro-mixer by two passages with a metering pump (the feed flow of the O-methylisourea sulfate solution is 6.2ml / min; The inlet flow rate of described mixed acid solution is mixed in 7.6ml / min),...