Method for synthesizing nitromethane

A technology of nitromethane and synthesis methods, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve the problems of nitromethane yield decline, easy generation of sparks, and influence on the distillation process, etc., to achieve beneficial Product purity and yield, avoiding the harm of Mars, and improving the effect of reaction yield

Inactive Publication Date: 2014-02-05
SHIJIAZHUANG TIEDAO UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] If the reaction temperature is too high, there will be two side effects
The first is that the decomposition of dimethyl sulfate is accelerated, and the sulfuric acid generated by the decomposition reduces the pH of the reaction system, the catalytic effect of soda ash is reduced, and the reaction time is prolonged, and the decomposition of the raw material dimethyl sulfate causes the incomplete reaction of sodium nitrite to cause the total yield Reduced, product purity decreased
The second is that the reaction temperature is too high will make the side reaction product methyl nitrite (CH 3 ONO) increased, which further led to a decrease in the total yield of the reaction, and made the rectification process prone to generate sparks and other factors that endanger the environment and safety
[0016] After the reaction is over, simple filtration to remov

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0045] Example 1

[0046] In a four-necked flask equipped with an electric stirrer, a reflux condenser, a constant pressure dropping funnel and a thermometer, add 69 grams (1 mol) of sodium nitrite and 30 milliliters of water, respectively, and add sodium carbonate to make the pH of the reaction solution between 11 Between -12, add 0.03mol phase transfer catalyst dodecyl trimethyl ammonium chloride, add 50 ml of diethyl ether as solvent, add 63 g (0.5mol) dimethyl sulfate dropwise under stirring, and control the dimethyl sulfate The dropping rate of the ester is controlled at 30°C-35°C, the dropwise addition is completed, and the reaction is completed after 3 hours of incubation. After-treatment: the reaction solution was cooled to minus 27.5°C under stirring, the water was in the form of crushed ice, water and solid by-products were precipitated, filtered, and the solid-liquid two phases were separated. The separated liquid phases were combined, and after the solvent was rec...

Example Embodiment

[0047] Example 2

[0048] In a four-necked flask equipped with an electric stirrer, a reflux condenser, a constant pressure dropping funnel and a thermometer, add 69 grams (1 mol) of sodium nitrite and 35 milliliters of water, respectively, and add sodium carbonate to make the pH of the reaction solution between 10 Between -11, add 0.03mol of phase transfer catalyst tetrabutylammonium chloride, add 30 ml of dichloromethane as a solvent, add 63 g (0.5mol) of dimethyl sulfate dropwise under stirring, by controlling the concentration of dimethyl sulfate The dropping speed was controlled to control the temperature at 35°C-40°C, the dropwise addition was completed, and the incubation reaction was completed after 3 hours. After-treatment: the reaction solution was cooled to minus 22°C under stirring, and the water was in the form of crushed ice, so that water and solid by-products were precipitated, filtered, and the solid-liquid two phases were separated, and the solid phase was wa...

Example Embodiment

[0049] Example 3

[0050] In a four-necked flask equipped with an electric stirrer, a reflux condenser, a constant pressure dropping funnel and a thermometer, add 69 grams (1 mol) of sodium nitrite and 30 milliliters of water, respectively, and add sodium carbonate to make the pH of the reaction solution between 11 Between -12, add 0.035mol phase transfer catalyst 18-crown-6, add 10 ml of diethyl ether and 20 ml of methyl propyl ether as solvent, add 63 g (0.5mol) dimethyl sulfate dropwise under stirring, by controlling the diethyl sulfate The rate of addition of methyl ester was controlled at 34°C-40°C, the dropwise addition was completed, and the reaction was completed after 4 hours of incubation. After-treatment: the reaction solution was cooled to minus 25°C under stirring, the water was in the form of crushed ice, water and solid by-products were precipitated, filtered, and the solid-liquid two phases were separated, and the solid phase was washed twice with 60 ml of ethy...

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PUM

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Abstract

The invention discloses a method for synthesizing nitromethane, and relates to the technical field of synthesis of compounds with nitryl connected to a saturated noncyclic carbon atom. The method comprises the following steps: stirring and dissolving raw materials sodium nitrite; dripping a raw material dimethyl sulfate in a stirring state, and reacting; filtering the reaction liquid under a stirring state in the post-treatment, separating solid and liquid phases, decompressing and distilling the liquid phase to obtain a nitromethane coarse product, and rectifying to obtain a nitromethane finished product; adding a solvent and a phase transfer catalyst before the raw material dimethyl sulfate is dripped, wherein the boiling point of the solvent is lower than 100 DEG C, the solvent is used for controlling the reaction temperature, and the reaction temperature is 20-60 DEG C. According to the method, the reaction temperature can be easily controlled, the generation of a side product methyl nitrite can be reduced, the reaction yield can be improved, and spark generated in the rectifying process can be reduced, potential safety hazard can be reduced, and the product purity can be increased.

Description

technical field [0001] The invention relates to the technical field of synthesis of compounds with nitro group connected to saturated non-ring carbon atoms. Background technique [0002] Nitromethane is an important organic chemical product and organic synthesis intermediate. It is a colorless, transparent, oily liquid with aroma and certain volatility. ), a refractive index of 1.3817, and a flash point of 35°C; it is partially soluble in water, and its aqueous solution is acidic, soluble in alcohol, ether, acetone, carbon tetrachloride, dimethylformamide and caustic alkali solution. [0003] Nitromethane is miscible with most organic compounds and is an excellent solvent for aromatic hydrocarbons, alcohols, ketones, ethers, esters and carboxylic acid compounds. It has the characteristics of good selectivity, low viscosity, and low volatility. It is widely used in the synthesis of polymer materials, and can also be used in the production of explosives, rocket fuel, pesticid...

Claims

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Application Information

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IPC IPC(8): C07C205/02C07C201/10
Inventor 杨晋辉陈艳雪
Owner SHIJIAZHUANG TIEDAO UNIV
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