Synthetic method for benzotriazole ultraviolet absorbent UV-P

A UV-P, benzotriazole technology, applied in organic chemistry and other directions, can solve problems such as difficulty in large-scale production, poor product quality, and complicated post-processing, and achieve easy large-scale production, low cost, and convenient post-processing. Effect

Active Publication Date: 2013-10-16
TIANCHANG TIANJIA CHEM TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0018] Aiming at the problems of low yield, poor product quality, unfriendly environment, complex post-processing and difficult large-scale production of the production method of UV-P in the prior art, the invention provides a benzotriazole ultraviolet absorber UV- The synthetic method of P, described method is with o-nitroazo compound as raw material, obtains benzotriazole compound UV-P through reduction ring closure

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  • Synthetic method for benzotriazole ultraviolet absorbent UV-P
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  • Synthetic method for benzotriazole ultraviolet absorbent UV-P

Examples

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Embodiment 1

[0052] A preparation method for UV-P, comprising the steps of:

[0053] (1) Using the azo intermediate (II) as the raw material, the nitrogen oxide (III) can be obtained by reduction:

[0054] In a 500mL three-neck flask equipped with a stirrer and a reflux condenser, add 250g of dichloromethane, 25g of azo intermediates, and 15.17g of sodium sulfide in sequence, stir and raise the temperature to 40°C, heat and reflux at this temperature for 5h, and the reaction ends Afterwards, the reaction temperature was lowered to room temperature, and the reaction solution changed from dark red to earthy yellow. 200g of water was added into the reaction flask, stirred, extracted, the dichloromethane layer was dried, filtered, and the obtained filtrate was dissolved with nitrogen oxides (Ⅲ ) in dichloromethane, and the filtrate was kept for the next reduction.

[0055] (2) Using an organic solvent dissolved with nitrogen oxide (Ⅲ) as a raw material, catalytic reduction hydrogenation is us...

Embodiment 2

[0059] A preparation method for UV-P, comprising the steps of:

[0060] (1) Using the azo intermediate (II) as the raw material, the nitrogen oxide (III) can be obtained by reduction:

[0061] In a 500mL three-necked flask equipped with a stirrer and a reflux condenser, add 250g of 1,2-dichloroethane, 25g of azo intermediates, and 15.17g of sodium sulfide in sequence, stir and raise the temperature to 83°C, and heat to reflux at this temperature 4h, after the reaction was completed, the reaction temperature dropped to room temperature, the reaction solution changed from purple red to khaki, 200g of water was added into the reaction flask, stirred, extracted, the 1,2-dichloromethane layer was dried, filtered, and the obtained filtrate was For 1,2-dichloromethane dissolved with nitrogen oxide (III), the filtrate was saved for the next reduction.

[0062] (2) Using an organic solvent dissolved with nitrogen oxide (Ⅲ) as a raw material, catalytic reduction hydrogenation is used t...

Embodiment 3

[0066] A preparation method for UV-P, comprising the steps of:

[0067] (1) Using the azo intermediate (II) as the raw material, the nitrogen oxide (III) can be obtained by reduction:

[0068] In a 500mL three-necked flask equipped with a stirrer and a reflux condenser, add 114g of 1,2-dichloroethane, 0.1mol of azo intermediates, and 0.1mol of sodium sulfide in sequence, stir and raise the temperature to 88°C, and heat at this temperature Reflux for 2 hours. After the reaction, the reaction temperature dropped to room temperature, and the reaction solution changed from purple red to khaki. Add 100 g of water into the reaction flask, stir, extract, dry the 1,2-dichloromethane layer, and filter to obtain the filtrate It is 1,2-dichloromethane dissolved with nitrogen oxide (Ⅲ), and the filtrate is reserved for the next step of reduction.

[0069] (2) Using an organic solvent dissolved with nitrogen oxide (Ⅲ) as a raw material, catalytic reduction hydrogenation is used to prepare...

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Abstract

The invention relates to a synthetic method for 2-(2'-hydroxy-methylphenyl) benzotriazole (UV-P). The method comprises the following steps: (1) with an azo intermediate (II) as a raw material and sodium sulfide as a reducing agent, carrying out a reduction reaction in an organic solvent so as to obtain an organic solution with dissolved nitrogen oxide (III); and (2) with the organic solution containing dissolved nitrogen oxide (III) obtained in the step (1) as a raw material, carrying out a catalytic reduction hydrogenation reaction in the presence of a reducing catalyst so as to obtain the UV-P (I). Compared with the prior art, the invention has the following advantages: the two-step reduction method is adopted, the azo intermediate (II) is used as the raw material for preparation of the UV-P, and yield of the UV-P is as high as more than 80%; the organic solvent is easy to recover, the application amount of sodium hydroxide is small, and little environmental pollution is produced; cost is low, post-treatment is convenient, and large scale production can be easily carried out.

Description

technical field [0001] The invention relates to a synthesis method of a benzotriazole ultraviolet absorber UV-P, in particular to a method for reducing and closing an o-nitroazo compound into a benzotriazole compound UV-P. Background technique [0002] Benzotriazole light stabilizers were successfully developed by Ciba-Geigy in Switzerland in the 1970s. This type of light stabilizer can strongly absorb high-energy ultraviolet light and convert the energy into heat or light, thereby reducing or releasing the energy. The benzotriazole ultraviolet absorber can absorb light in the wavelength range of 290-400nm, has the advantages of low volatility, low toxicity, stability, and good compatibility with polymer materials. Benzotriazole stabilizers are the most commonly used and most effective UV absorbers in plastics, which can effectively prevent or delay the aging of polymer materials. 2-(2'-Hydroxy-5'-methylphenyl)benzotriazole (UV-P) is a representative product in this catego...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D249/18
Inventor 孙郁张春涛纪奉元
Owner TIANCHANG TIANJIA CHEM TECH
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