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Preparation method of alpha-bromo aromatic ketone compounds

A technology for aromatic ketones and compounds, which is applied in the field of preparation of α-bromoaromatic ketones, can solve the problems of high price and environmental pollution, and achieve the effects of high selectivity, reduced production costs, and mild reaction conditions

Inactive Publication Date: 2018-07-13
NINGXIA PAGODA CHEM CENT LAB CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present invention provides a kind of high-efficiency, green α-bromoaromatic ketone compound preparation method, main purpose is to solve the high price of using bromine, heavy metal bromide salt, NBS etc. Environmental Pollution

Method used

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  • Preparation method of alpha-bromo aromatic ketone compounds
  • Preparation method of alpha-bromo aromatic ketone compounds

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] At room temperature, add 16.2g (0.1mol) of valerophenone and 30.9g (0.3mol) of sodium bromide into a 500 mL round-bottomed flask, stir well, then add 24g (0.2mol) of 30% hydrochloric acid, and slowly Add 19g (0.15mol) of 30% hydrogen peroxide dropwise. After the dropwise addition, continue to react for 1~2h. After the reaction is monitored by TLC, stop stirring, let stand to separate layers, wash with saturated sodium carbonate and saturated saline respectively, and combine organic phase, concentrated and dried over anhydrous magnesium sulfate to obtain α-bromovalerophenone, a bright yellow oily liquid with a yield of 95% and a purity of 98% (HPLC method).

[0024]

Embodiment 2

[0026] Add 19.6g (0.1mol) of p-chlorovalerone to a 500mL round bottom flask equipped with a reflux condenser, add 50mL of methanol and stir to dissolve, then add 30.05g (0.35mol) of sodium bromide, stir well, Add 25.3g (0.25mol) of 36% hydrochloric acid, and slowly add 25.3g (0.2mol) of 30% hydrogen peroxide dropwise. After the dropwise addition, raise the temperature to 70~75°C and continue the reaction for 1~2h. TLC monitors the reaction after the end , stop stirring, let stand to separate layers, wash with saturated sodium carbonate and saturated brine respectively, combine the organic phases, concentrate and dry over anhydrous magnesium sulfate to obtain p-chloro α-bromovalerophenone, yellow oily liquid, yield 96 %, purity 96% (HPLC method).

Embodiment 3

[0028] At room temperature, add 13.4g (0.1mol) of propiophenone and 41.2g (0.4mol) of sodium bromide to a 500 mL round bottom flask respectively, after stirring evenly, add 32.7g (0.1mol) of 30% sulfuric acid, and slowly Add 35.2g (0.25mol) of 27% hydrogen peroxide dropwise. After the dropwise addition, continue to react for 1~2h. After the reaction is monitored by TLC, stop stirring, let stand to separate layers, wash with saturated sodium carbonate and saturated saline respectively, and combine The organic phase was concentrated and dried over anhydrous magnesium sulfate to obtain α-bromopropiophenone, a yellow oily liquid with a yield of 94% and a purity of 96% (HPLC method).

[0029]

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Abstract

The invention discloses a high-efficiency and green preparation method of alpha-bromo aromatic ketone compounds. The preparation method comprises that under a certain temperature, alpha-H of aromaticketone compounds is brominated to prepare the alpha-bromo aromatic ketone compounds in an acidic medium with hydrogen peroxide as an oxidant and an inorganic bromide as a bromine source under the condition of an alcoholic solvent or solvent-free. The main features of the method are that bromination reagents such as bromine, bromine dioxane, 2,4,4,6-tetrabromocycloketone, perbrominated quaternary ammonium salts, C5H5N.HBr.Br, NBS, dibromohydantoin, copper bromide and cuprous bromide are not used as the bromine source, so that production cost is reduced, and environmental pollution caused by heavy metal bromination reagents is avoided; and in addition, the method uses hydrogen peroxide and inorganic bromide reagents to prepare the alpha-bromo aromatic ketone compounds in situ, the reaction conditions are mild, the experimental operation is simple, the selectivity is good, and the product is single, and therefore, the preparation method has very high applicability and universality, and has a very broad application prospect.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a preparation method of α-bromoaromatic ketones. Background technique [0002] α-Bromoaromatic ketones are important intermediates in organic synthesis, widely used in the synthesis of medicines, pesticides and functional chemicals. For example: α-bromoacetophenone is an important intermediate of non-steroidal anti-inflammatory drugs arylpropionic acid, and p-methoxy-α-bromoacetophenone is the main intermediate of synthetic estrogen drug raloxifene They are usually prepared by the α-bromination of the corresponding aromatic ketones. [0003] At present, there are many reports on the α-position bromination reaction methods of aromatic ketone compounds, but most of them are used in organic solvents such as ether, dichloromethane, ethyl acetate, N,N-dimethylformamide, etc., with bromine, bromine Dioxane, 2,4,4,6-tetrabromocyclone, perbrominated quaternary ammonium salt, C 5 h 5 ...

Claims

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Application Information

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IPC IPC(8): C07C45/63C07C49/80C07C49/84
CPCC07C45/63C07C49/80C07C49/84
Inventor 张和李晓静陆世鹏贾昕李菲菲徐建
Owner NINGXIA PAGODA CHEM CENT LAB CO LTD
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