5-chloro-2-pentanone preparation method

A pentanone and cyclic chlorination technology, applied in the field of medicine and chemical industry, can solve the problems of cumbersome post-processing, large amount of waste water, complicated process, etc., and achieve the effects of reducing production cost, improving utilization rate and high yield

Active Publication Date: 2014-04-02
JIANGSU QINGQUAN CHEM CO LTD
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Problems solved by technology

However, in these processes of the prior art, there are problems such as complicated after-treatment, large amount of waste water, low catalyst utilization rate, complex process, and long reaction time.
In addition, in these processes, hydrochloric acid will have an adverse effect on the hydrogenation catalyst, such as after a long time of reaction, hydrochloric acid will reduce its catalyst activity and reduce its catalyst life
In the more traditional reaction process, thionyl chloride, phosphorus oxychloride, phosphorus pentachloride, etc. are used as chlorinating agents; the recovery of by-products is difficult, and waste water and waste gas are difficult to handle; these are still to be solved question

Method used

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  • 5-chloro-2-pentanone preparation method

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Embodiment 1

[0022] Put 540kg of 2-methylfuran and 3kg of palladium-carbon catalyst (containing 5wt% palladium and 55wt% water) into the reactor, first replace it with nitrogen three times, stir and cool down to below 5°C, then replace it with hydrogen three times, and then continue For hydrogenation reaction, the pressure is controlled at 0.05-0.15MPa, and the temperature is between 5-15°C; when the content of 2-methyl-4,5-dihydrofuran reaches above 95% (GC value), the reaction ends and the addition is stopped. Hydrogen, the reaction time is about 8 hours. After replacing the hydrogen with nitrogen and filtering the catalyst in the reaction material in the separation tank, the filtrate is transferred to a halogenation metering tank for use. Add 2000kg of 15%-20% hydrochloric acid solution into the halogenation kettle, open the jacketed steam valve, heat up and stir to reach the reflux state, and when heated to 65°C, add dropwise 2-methyl-4,5 from the halogenation metering tank - Dihydrof...

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Abstract

The present invention provides a 5-chloro-2-pentanone preparation method, which comprises that: 2-methyl furan is subjected to a hydrogenation reaction in the presence of a hydrogenation catalyst and hydrogen gas to prepare 2-methyl-4,5-dihydrofuran, and the 2-methyl-4,5-dihydrofuran and hydrochloric acid are subjected to a ring opening chlorination reaction to obtain the 5-chloro-2-pentanone. According to the present invention, 2-methyl furan is adopted as the raw material, the reaction steps are simple and easy to operate, no wastewater is generated during the production process, and environmental protection requirements are met; the hydrogenation catalyst, the distillate and the hydrochloric acid can be recycled so as to substantially reduce the production cost, and the prepared product has characteristics of high yield and high purity; and compared with the conventional process, the preparation method of the present invention has characteristics of complete elimination of influence of hydrochloric acid on the catalyst, improvement of the catalyst utilization rate, and substantial reduction of the 5-chloro-2-pentanone production cost.

Description

technical field [0001] The invention relates to the field of medicine and chemical industry, in particular to a preparation method of 5-chloro-2-pentanone. Background technique [0002] 5-Chloro-2-pentanone is an important raw material for the synthesis of ciprofloxacin, ciprofloxacin and sparfloxacin, and is also widely used in the synthesis of pesticides and agricultural fine chemical products. The preparation method of 5-chloro-2-pentanone reported in the prior art is: using 2-methylfuran or gamma-butyrolactone as the starting material, catalytic hydrogenation separation under acidic conditions to obtain acetyl-n-propane Alcohol, followed by halogenation to 5-chloro-2-pentanone product. For example, Chinese patent application 201210099170 discloses a preparation method of cyclopropyl methyl ketone, which uses 2-acetyl-γ-butyrolactone as raw material and hydrochloric acid for chlorination reaction to obtain 5-chloro-2- Pentanone, 5-chloro-2-pentanone and liquid caustic s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/16C07C45/59
CPCC07C45/59C07D307/28C07C49/16
Inventor 郑端镛宁剑波徐威张浩周君张增礼吴小林
Owner JIANGSU QINGQUAN CHEM CO LTD
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