Synthesis technique of benzotriazole

A technology of benzotriazole and synthesis process, applied in the field of synthesis technology of benzotriazole, can solve the problems of separating products, recovering solvent, the danger of explosion of hydrazine hydrate, large amount of hydrazine hydrate, etc., and achieves convenient recovery. The effect of using, reducing the amount and reducing the production cost

Inactive Publication Date: 2013-01-16
陈守文
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  • Description
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Problems solved by technology

The cost of n-octanol used in this method is relatively high, and the amount of hydrazine hydrate is relatively large, and the method of separating products and recovering solvent is relatively complicated
The amou

Method used

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  • Synthesis technique of benzotriazole

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Effect test

Embodiment 1

[0020] Embodiment 1, with reference to figure 1 , a kind of synthesis technique of benzotriazole, its concrete steps are as follows:

[0021] (1) In the reaction kettle, add a certain amount of o-nitrochlorobenzene, dimethyl sulfoxide solvent with 0.5 times the mass of o-chloronitrobenzene, and 80% hydrazine hydrate with a molar ratio of two times the o-chloronitrobenzene; heat up to 115 Reflux at ℃ for 3 hours; add 40% NaOH solution in an equimolar amount to o-chloronitrobenzene to fully release the remaining hydrazine hydrate;

[0022] (2) Under reduced pressure, control the vacuum degree to 10kPa, raise the temperature of the oil bath, keep the oil temperature at 75°C for distillation, discard the initial 10% fraction, then collect and recover hydrazine hydrate; and raise the temperature to 135°C to recover dimethyl methoxide Sulfone;

[0023] (3) Add a certain amount of water to the residual liquid to completely dissolve the residue; adjust the pH to 3 with 10% hydrochlo...

Embodiment 2

[0025] Embodiment 2, with reference to figure 1 , a kind of synthesis technique of benzotriazole, its concrete steps are as follows:

[0026] (1) In the reaction kettle, add a certain amount of o-nitrochlorobenzene, dimethyl sulfoxide solvent with 2 times the mass of o-chloronitrobenzene, and 80% hydrazine hydrate with a molar ratio of 5 times the o-chloronitrobenzene; heat up to 115 Reflux at ℃ for 5 hours; add 40% NaOH solution in an equimolar amount to o-chloronitrobenzene to fully release the remaining hydrazine hydrate;

[0027] (2) Under reduced pressure, control the vacuum degree to 20kPa, raise the temperature of the oil bath, keep the oil temperature at 80°C for distillation, discard the initial 10% fraction, then collect and recover hydrazine hydrate; and raise the temperature to 140°C to recover dimethyl methoxide Sulfone;

[0028] (3) Add a certain amount of water to the residual liquid to completely dissolve the residue; adjust the pH to 3.5 with 10% hydrochlori...

Embodiment 3

[0030] Embodiment 3, with reference to figure 1 , a kind of synthesis technique of benzotriazole, its concrete steps are as follows:

[0031] (1) In the reaction kettle, add a certain amount of o-nitrochlorobenzene, dimethyl sulfoxide solvent with 1 times the mass of o-chloronitrobenzene, and 80% hydrazine hydrate with a molar ratio of 3.5 times o-chloronitrobenzene; heat up to 115 Reflux at ℃ for 4 hours; add 40% NaOH solution in an equimolar amount to o-chloronitrobenzene to fully release the remaining hydrazine hydrate;

[0032] (2) Under reduced pressure, control the vacuum degree to 15kPa, raise the temperature of the oil bath, keep the oil temperature at 78°C for distillation, discard the initial 10% fraction, then collect and recover hydrazine hydrate; and raise the temperature to 137°C to recover dimethyl methoxide Sulfone;

[0033] (3) Add a certain amount of water to the residual liquid to completely dissolve the residue; adjust the pH to 3.2 with 10% hydrochloric ...

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Abstract

The invention relates to a synthesis technique of benzotriazole, which comprises the following two reaction steps: 1. reacting o-chloronitrobenzene and hydrazine hydrate to generate 1-hydroxybenzotriazole (HBTA), wherein DMSO (dimethyl sulfoxide) is used as a solvent to implement synthetic reaction of HBTA under homogeneous conditions; and 2. reacting the HBTA and reduced iron powder to generate the benzotriazole product. The DMSO with strong polarity promotes the reaction, so that the hydrazine hydrate can be added at one time, and the consumption of the hydrazine hydrate is reduced as compared with the existing technique; and meanwhile, the DMSO and hydrazine hydrate can be conveniently recovered. In the after-treatment process of preparing benzotriazole by reducing the HBTA, the salting-out mode is utilized to separate the product, thereby greatly enhancing the production efficiency and lowering the production cost as compared with the existing extraction method.

Description

technical field [0001] The invention belongs to a synthesis process of benzotriazole; it is mainly used as a corrosion inhibitor for copper and copper alloys, a metal antirust agent and an organic synthesis intermediate. Background technique [0002] Benzotriazole (BTA) is an important fine chemical product. It has a wide range of uses, mainly used as corrosion inhibitors for copper and copper alloys, photographic antifogging agents, metal antirust agents and organic synthesis intermediates; it is also widely used in paint additives, lubricating oil additives, synthetic dye intermediates, synthetic washing Preservatives, anticoagulants, polymer material stabilizers, plant growth regulators, anti-tarnish agents, gas phase corrosion inhibitors, UV absorbers, and analytical reagents. [0003] With its excellent corrosion inhibition performance, good synergistic effect with other components and wide adaptability to metals and media, BTA is widely used in various industries ...

Claims

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Application Information

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IPC IPC(8): C07D249/18
Inventor 陈守文
Owner 陈守文
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