Method for producing civil dinitrotoluene

Abstract

The invention provides a new technique for synthesized civil (DNT) with good quality, which regards toluene and nitric acid as raw materials, concentrated sulfuric acid as catalyst, and carbon tetrachloride with low boiling point as solvents; in certain conditions, the DNT is produced directly, the yield of the products can reach 96.4 percent, the purity is above 98 percent, and the quality of the products satisfies the first-rate standards, 2,4-DNT / 2,6-DNT is equal to 80 plus or minus 1 / 20 plus or minus 1, as organic solvent is introduced, little influence of temperature is caused towards the isomer ratio of products in reaction, and the conditions of nitration reaction are mild, the ratio of isomer produced is easy to be controlled, the density of waste liquid is high, and nitrate containing amount is low, which is beneficial for the concentration of waste liquid and the reduce of emission of waste water, primary nitrification and secondary nitrification are both carried on in the same reaction kettle, the technique is simple, the production cost is low, the requirement of environmental protection is satisfied, so the new technique for synthesized civil DNT with good quality hasrather great implementary value and social economic benefits.

Description

technical field

[0001] The invention belongs to the field of organic chemistry and relates to a preparation process of dinitrotoluene, in particular to a preparation process of civil standard dinitrotoluene (DNT). Background technique

[0002] Toluene is a heavy tonnage product of the petrochemical industry with low price and abundant sources. The development of its downstream products has always been valued by the chemical and chemical industry. Through deep processing of toluene, many valuable chemical products can be produced, such as oxidation to produce benzyl alcohol, benzoic acid, chlorination to produce benzyl chloride, sulfonation to produce toluenesulfonic acid, nitration to produce 2-nitrotoluene, 3-nitrotoluene A series of important pharmaceutical intermediates such as methyl toluene and p-nitrotoluene can increase its added value many times and have considerable economic benefits.

[0003] Among the downstream products of toluene, dinitrotoluene (DNT) is an imp...

Examples

Embodiment 1

[0021] One-stage nitration: add 4mL of carbon tetrachloride and 4mL of toluene in turn into a 100mL pear-shaped flask, raise the temperature to 50°C and slowly add 1.8mL of fuming nitric acid dropwise, and react for 20min.

[0022] Two-stage nitration: Slowly add 7mL of concentrated sulfuric acid (concentration: 98%) dropwise, add 2.4mL of fuming nitric acid dropwise after heating up to 65°C, and continue stirring for 60min.

[0023] Post-reaction treatment: after the reaction, let stand to separate the layers, then separate the organic phase while it is hot, distill off the solvent carbon tetrachloride to precipitate the product DNT; Chloromethane precipitates the product DNT. The combined product DNT was first washed with a sodium carbonate solution of about 2.5% DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed and Take an appropriate am...

Embodiment 2

[0025] One stage nitration: Add 8mL of carbon tetrachloride and 4mL of toluene into a 100mL pear-shaped flask in sequence, and slowly add 1.8mL of fuming nitric acid and 7mL of concentrated sulfuric acid (concentration 98.2%) dropwise after heating up to 30°C. React for 30 minutes.

[0026] Two-stage nitration: After heating up to 65°C, add 2.4mL of fuming nitric acid dropwise, and continue stirring for 60min.

[0027] Post-reaction treatment: After the reaction is over, let stand to separate layers, then separate the organic phase while it is hot, and distill the organic phase to remove the solvent carbon tetrachloride to precipitate the product DNT; The solvent chloroform precipitates the product DNT. The combined product DNT was first washed with a sodium carbonate solution of about 3% DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed an...

Embodiment 3

[0029] One-stage nitration: add 8mL of carbon tetrachloride and 4mL of toluene into a 100mL pear-shaped flask in sequence, raise the temperature to 50°C and slowly add 1.8mL of fuming nitric acid dropwise, and react for 10min.

[0030] Two-stage nitration: Slowly add 7mL of concentrated sulfuric acid (98.2%) dropwise, after heating up to 65°C, add 2.4mL of fuming nitric acid dropwise, and continue stirring for 90min.

[0031] Post-reaction treatment: after the reaction, let stand to separate the layers, then separate the organic phase while it is hot, distill off the solvent carbon tetrachloride to precipitate the product DNT; Chloromethane precipitates the product DNT. The combined product DNT was first washed with 3.5% sodium carbonate solution of DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed and taken Appropriate amount of DNT for ga...

technical field

[0001] The invention belongs to the field of organic chemistry and relates to a preparation process of dinitrotoluene, in particular to a preparation process of civil standard dinitrotoluene (DNT). Background technique

[0002] Toluene is a heavy tonnage product of the petrochemical industry with low price and abundant sources. The development of its downstream products has always been valued by the chemical and chemical industry. Through deep processing of toluene, many valuable chemical products can be produced, such as oxidation to produce benzyl alcohol, benzoic acid, chlorination to produce benzyl chloride, sulfonation to produce toluenesulfonic acid, nitration to produce 2-nitrotoluene, 3-nitrotoluene A series of important pharmaceutical intermediates such as methyl toluene and p-nitrotoluene can increase its added value many times and have considerable economic benefits.

[0003] Among the downstream products of toluene, dinitrotoluene (DNT) is an imp...

Examples

Embodiment 1

[0021] One-stage nitration: add 4mL of carbon tetrachloride and 4mL of toluene in turn into a 100mL pear-shaped flask, raise the temperature to 50°C and slowly add 1.8mL of fuming nitric acid dropwise, and react for 20min.

[0022] Two-stage nitration: Slowly add 7mL of concentrated sulfuric acid (concentration: 98%) dropwise, add 2.4mL of fuming nitric acid dropwise after heating up to 65°C, and continue stirring for 60min.

[0023] Post-reaction treatment: after the reaction, let stand to separate the layers, then separate the organic phase while it is hot, distill off the solvent carbon tetrachloride to precipitate the product DNT; Chloromethane precipitates the product DNT. The combined product DNT was first washed with a sodium carbonate solution of about 2.5% DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed and Take an appropriate am...

Embodiment 2

[0025] One stage nitration: Add 8mL of carbon tetrachloride and 4mL of toluene into a 100mL pear-shaped flask in sequence, and slowly add 1.8mL of fuming nitric acid and 7mL of concentrated sulfuric acid (concentration 98.2%) dropwise after heating up to 30°C. React for 30 minutes.

[0026] Two-stage nitration: After heating up to 65°C, add 2.4mL of fuming nitric acid dropwise, and continue stirring for 60min.

[0027] Post-reaction treatment: After the reaction is over, let stand to separate layers, then separate the organic phase while it is hot, and distill the organic phase to remove the solvent carbon tetrachloride to precipitate the product DNT; The solvent chloroform precipitates the product DNT. The combined product DNT was first washed with a sodium carbonate solution of about 3% DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed an...

Embodiment 3

[0029] One-stage nitration: add 8mL of carbon tetrachloride and 4mL of toluene into a 100mL pear-shaped flask in sequence, raise the temperature to 50°C and slowly add 1.8mL of fuming nitric acid dropwise, and react for 10min.

[0030] Two-stage nitration: Slowly add 7mL of concentrated sulfuric acid (98.2%) dropwise, after heating up to 65°C, add 2.4mL of fuming nitric acid dropwise, and continue stirring for 90min.

[0031] Post-reaction treatment: after the reaction, let stand to separate the layers, then separate the organic phase while it is hot, distill off the solvent carbon tetrachloride to precipitate the product DNT; Chloromethane precipitates the product DNT. The combined product DNT was first washed with 3.5% sodium carbonate solution of DNT mass until the pH value was 7-8, then washed 2 to 3 times with an appropriate amount of water, pre-dried at room temperature for one day, then vacuum-dried to constant weight, weighed and taken Appropriate amount of DNT for ga...

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