Preparation method of 2-methylamino-5-chlorobenzophenone

A technology of chlorobenzophenone and methylamino, which is applied in the field of medicine and chemical industry, can solve the problems of difficult to stir, stop the reaction, and high cost of solvents, achieve good structural stability, reduce additional costs, and avoid toxicity hazards

Inactive Publication Date: 2015-10-28
HUAZHONG PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The disadvantages are: using dimethyl sulfate as a methylation reagent, which is highly toxic and troublesome to deal with after the reaction; there are many steps, the total yield is lower by 77.6%, and the cost is high
The disadvantages are: the use of dimethyl sulfate as a methylation reagent is highly toxic and troublesome to deal with after the reaction; it is inconvenient to use powdered sodium hydroxide, and the heterogeneous reaction is incomplete; tetrahydrofuran or benzene is used as the reaction solvent, and the post-treatment Need to use ethyl acetate, high solvent cost
The reaction needs to be carried out under the protection of an inert gas. The reaction liquid is relatively viscous, difficult to stir,

Method used

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  • Preparation method of 2-methylamino-5-chlorobenzophenone
  • Preparation method of 2-methylamino-5-chlorobenzophenone
  • Preparation method of 2-methylamino-5-chlorobenzophenone

Examples

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preparation example Construction

[0035] Preparation of NaY Molecular Sieve with High Si-Al Ratio and Small Grain

[0036] The hydrothermal synthesis method is used to synthesize NaY molecular sieves with high silicon-aluminum ratio and small crystal grains by increasing the ratio of silicon to aluminum in the framework on the basis of controlling the grain size. The molecular sieve has good structural stability and catalytic activity, and the preparation method has easy-to-obtain raw materials, simple operation, low production cost and no environmental pollution, and has industrial application prospects.

[0037] The preparation method of NaY molecular sieve with high silicon-aluminum ratio and small grain size:

[0038] 21g sodium hydroxide and 7.2g sodium aluminate (ωAl 2 o 3 )≥41.0 %) was dissolved in 80g deionized water, stirred until clear, then added 125g water glass (ω(Na 2 O) = 6.98 %; ω(SiO 2 ) = 19.68 %), the directing agent was obtained by rotating and dynamically aging at 80°C for 12 h and at ...

Embodiment 1

[0046] Weigh 231g of 2-amino-5-chlorobenzophenone, 900g of dimethyl carbonate and 70g of NaY molecular sieve with high silicon-aluminum ratio and small crystal grains, and place them in a reaction flask. Stir and heat to 80°C. After the heat preservation reaction for 8 hours, the sample was analyzed, and the content of the raw material 2-amino-5-chlorobenzophenone in the reaction solution was found to be 0.2%, and the reaction could be stopped.

[0047] Pass water to cool to room temperature, remove the catalyst by filtration, transfer the filtrate to a decompression flask, distill off the unreacted dimethyl carbonate under reduced pressure, recrystallize the residue with ethanol to obtain yellow needle crystals, and obtain 2-methylamino -5-Chlorobenzophenone 221 g, yield 90.2%, melting point 94.0-95.1°C, HPLC purity 98.9%.

Embodiment 2

[0049] Weigh 231g of 2-amino-5-chlorobenzophenone, 900g of dimethyl carbonate and 186g of NaY molecular sieve with high silicon-aluminum ratio and small crystal grains, and place them in a reaction flask. Stir and heat to 90°C. After 6.5 hours of heat preservation reaction, sampling and analysis showed that the content of the raw material 2-amino-5-chlorobenzophenone in the reaction solution was 0.3%, and the reaction could be stopped.

[0050] Pass water to cool to room temperature, remove the catalyst by filtration, transfer the filtrate to a decompression flask, distill off the unreacted dimethyl carbonate under reduced pressure, recrystallize the residue with ethanol to obtain yellow needle crystals, and obtain 2-methylamino -5-Chlorobenzophenone 225 g, yield 91.8%, melting point 94.2-95.1°C, HPLC purity 98.7%.

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Abstract

The invention discloses a preparation method of 2-methylamino-5-chlorobenzophenone. The method includes the steps of: under the action of a catalyst, subjecting 2-amino-5-chlorobenzophenone and dimethyl carbonate to methylation reaction, thus obtaining 2-methylamino-5-chlorobenzophenone. Compared with existing preparation methods, the method has the advantages of simple preparation, low reaction reagent toxicity, high catalytic activity and selectivity, green and environmental protection and reusable catalyst, easy separation and purification of product, and small equipment corrosion and environmental pollution, can acquire high purity end-product, and is suitable for industrial production, etc.

Description

technical field [0001] The invention belongs to the technical field of medicine and chemical industry, and relates to a preparation method of 2-methylamino-5-chlorobenzophenone. Background technique [0002] 2-Methylamino-5-chlorobenzophenone is often used as a pharmaceutical intermediate, mainly used in the preparation of sedative drugs such as chlordiazepoxide, diazepam (diazepam), and diazepam. [0003] The preparation method of currently known 2-methylamino-5-chlorobenzophenone mainly contains two kinds: [0004] (1) 3-phenyl-5-chloro-2,1-benzisoxazole method [0005] Methylate 3-phenyl-5-chloro-2,1-benzoisoxazole with dimethyl sulfate to generate quaternary ammonium salt; then reduce it with iron powder to obtain 2-methylamino-5-chlorodiphenyl ketone. [0006] [0007] Shen Yiping [Pharmaceutical Industry, 1982, 5, 1-2] first reported the synthesis method. Guan Zuowu et al [Pharmaceutical Industry, 1983, 14 (3), 9-10] carried out methylation and reduction in two ...

Claims

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Application Information

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IPC IPC(8): C07C221/00C07C225/22B01J29/08
Inventor 冯旋付林廖俊李桂莲刘玉亭
Owner HUAZHONG PHARMA
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