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A kind of method for preparing bibefen

A technology for dibenzamide and dinitrotoluene, which is applied in the field of preparation of diphenhydramine, can solve problems such as poor product purity, low reaction yield, generation of impurities, etc., and achieves improved yield and content, broad market prospects, The effect of a good competitive advantage

Active Publication Date: 2018-04-24
SHENYANG SINOCHEM AGROCHEMICALS R&D CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] There is an obvious shortcoming in the synthesis method of bibefen reported in the literature: because 2,6-dichloro-3,5-dinitrotoluene (intermediate B) contains many electron-withdrawing groups, resulting in The hydrogen in the reaction is very lively, side reactions easily occur in the reaction, and impurities are produced, so that the reaction yield is lower (the average yield of this step is less than 50%), and the product purification is quite difficult, and the product purity is poor (column chromatography purification is required), so Not suitable for industrial production needs

Method used

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  • A kind of method for preparing bibefen

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Add 126g (0.5mol) of 2,6-dichloro-3,5-dinitrotoluene into a 500mL reaction flask, then add 250mL of DMF, raise the temperature to 50°C, and feed about 13.0g of ammonia gas within 2 hours ( 0.75mol), after the gas is passed through, keep it warm for 1 hour and take samples for analysis. After the reaction was analyzed by HPLC, the reaction was distilled under reduced pressure, and the solvent was removed to 100° C. at 0.09 MPa until no obvious fraction was separated. Approximately 200 mL of DMF was removed. Stop the precipitation, lower the temperature, drop the temperature in the container to 80°C, add 300mL of water to the reaction flask, stir at 50°C for 1 hour, cool down to room temperature, filter, wash with 60mL of water, and dry to obtain 108.4g of substituted amides, with a yield of 89.1 %, purity 95.1%.

[0042]Put 116g (0.5mol) of the substituted amide obtained in the above way, 126g (0.6mol) of 3,5-dichloro-4-fluoronitrobenzene, 138g (1.0mol) of potassium ca...

Embodiment 2

[0044] Add 48kg of 2,6-dichloro-3,5-dinitrotoluene and 100kg of DMF into the 300L reaction kettle, and pass 6.5kg (0.38kmol) of dry ammonia gas into the reaction flask within 3 hours while stirring. This reaction is an exothermic reaction, and the reaction temperature is 20°C, the highest not exceeding 40°C. Then the reaction was continued for 2 hours, and the reaction progress was tracked by liquid chromatography. After the reaction was complete, air was bubbled through for 1 hour to drive off excess ammonia gas.

[0045] The solvent is evaporated under reduced pressure, the vacuum is 0.095MPa, and the distillation is finished when the recovery rate of DMF is about 80%. After evaporating the solvent, slowly add 110L of water at 80°C, but not too fast, otherwise the temperature will drop too quickly to form large solids, and then stir at 60°C for 0.5 hours. Cool down to 20°C, filter, wash with 20 L of water, and dry to obtain 43 kg of substituted amides with a yield of 95.9%...

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Abstract

The invention belongs to the field of organic synthesis and particularly relates to a preparation method of SYP-14288. The method includes the steps of: adding a reaction solvent A to 2,6-dichloro-3,5-dinitrotoluene, adding dropwisely ammonia water or feeding ammonia gas to the solution at from 0 DEG C to reflux temperature of the solvent A, continuously performing the reaction for 1-10 h, and removing the solvent after the reaction is finished to obtain an intermediate substituted ammoniated substance; performing a reaction to the substituted ammoniated substance, 3,5-dichloro-4-fluoronitrobenzene, an alkali and a reaction solvent B for 1-20 h at from room temperature to reflux condition of the solvent B; and removing the solvent after the reaction is finished, performing post-treatment to obtain a crude product, and re-crystallizing the crude product to obtain the product, SYP-14288. The product SYP-14288 is high in purity and yield. The method employs easy-to-obtained raw materials, has simple operations and mild reaction conditions, and is suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for preparing bibefen. Background technique [0002] Chinese patent application CN102199095 (A) discloses bibexenil (compound I) with bactericidal activity, and its structural formula is as follows: [0003] [0004] The results of biological tests show that the compound has excellent biological activity and a wide bactericidal spectrum. At a concentration of 1 mg / L, it can be effective against peach brown rot, corn curvularia, rice sheath blight, watermelon anthracnose, corn small spot, pear black star The bacteria, cotton anthracnose, cotton Verticillium dahliae, and rape sclerotinia have a bacteriostatic rate of more than 95%, which has broad market prospects. The above-mentioned patent application discloses the preparation method of the compound at the same time. Bibefen (compound 43) was prepared as follows: [0005] [0006] There is an obvious...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C209/10C07C211/56A01N33/18A01P3/00
Inventor 白丽萍吴公信刘淑杰李慧超刘长令
Owner SHENYANG SINOCHEM AGROCHEMICALS R&D CO LTD
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