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Method for synthesizing alpha-bromo-acetophenone

A technology of bromoacetophenone and acetophenone, which is applied in the field of α-bromination to replace acetophenone, can solve the problems of unused cost, low product purity, and pungent odor, and achieve easy The effect of industrialized production and laboratory operation, simple process and low price

Inactive Publication Date: 2006-02-15
EAST CHINA NORMAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Another method is to use dibromohydantoin (DBDMH) in CCl 4 Reaction with acetophenone in α-bromoacetophenone (‘Halogenation of Ketones with dibromodimethylhadantion’Orazi; Meseri; An.Asoc.Quim.Argent.; 38; 1950; 300, 306), but CCl 4 It has irritating smell, high toxicity and troublesome preparation. With this method (the mechanism of free radical reaction), only 59% yield can be obtained, and the product purity is not high, and there is almost no practical use value.

Method used

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  • Method for synthesizing alpha-bromo-acetophenone
  • Method for synthesizing alpha-bromo-acetophenone
  • Method for synthesizing alpha-bromo-acetophenone

Examples

Experimental program
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Embodiment 1

[0020] Example 1: Add 8.6mmol of acetophenone, 4.3mmol of p-toluenesulfonic acid, 15mL of methanol into a 100mL three-neck flask, and stir at 20°C. Add dropwise 6.4mmol of DBDMH in 25mL of methanol solution (dissolve 6.4mmol of 1,3-dibromo-5,5-dimethylhydantoin in 25ml of methanol solvent to prepare a DBDMH solution, which is convenient for dropwise addition). The reaction was completed in 6 hours. After the reaction, methanol was removed by rotary evaporation, and then about 80 mL of ice water was added for shaking. Solids were precipitated, filtered by suction, and vacuum-dried at room temperature to obtain white crystals, which were the product α-bromoacetophenone of the present invention. The yield was 88%, melting point 48-50°C (48-51°C in literature). Add sodium carbonate to the filtrate to neutralize to neutral, remove water under reduced pressure, wash the residue with acetone, filter, remove solvent, and recover hydantoin.

Embodiment 2

[0021] Example 2: Add 10 mmol m-nitroacetophenone, 2 drops of phosphoric acid, and 15 mL toluene into a 100 mL three-necked flask, and stir at 60° C. Add 7.5mmol of DBDMH in 25mL of toluene solution dropwise (dissolve 7.5mmol of 1,3-dibromo-5,5-dimethylhydantoin in 25ml of methanol solvent to prepare a DBDMH solution, which is convenient for dropwise addition). The reaction was completed in 5 hours. After the reaction was completed, the methanol was removed by rotary evaporation, and then about 80 mL of ice water was added for shaking, and a solid was precipitated, filtered by suction, and dried in vacuo at room temperature to obtain white crystals with a yield of 74% and a melting point of 92-94 ° C (document: 90 -94°C). Add sodium carbonate to the filtrate to neutralize to neutral, remove water under reduced pressure, wash the residue with acetone, filter, remove solvent, and recover hydantoin.

[0022] The acetophenone raw material that other 22 embodiments adopt and the p...

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Abstract

The invention discloses a process for synthesizing bromoacetophenone, which comprises measuring acetophenone : acids : DBDMH by the molar weight of 1 : 0.1-1.0 : 0.5-1.0, charging acetophenone and acid as catalyst into containers, stirring and elevating temperature to 10-100 deg. C, dropping DBDMH solution, reacting 4-8 hours, stopping the reaction, decompressing for removing the filter liquor, charging the filter residue into iced water, washing the filtering slag to neutral, filtering to obtain dust cake, drying the dust cakes, obtaining alpha-bromoacetophenone, charging sodium carbonate into the filter liquor for neutralizing, removing water, washing residue with acetone, filtering, removing solvent, reclaiming by-product hydantoin.

Description

technical field [0001] The invention discloses a method for synthesizing α-bromoacetophenone, relates to an α-bromination method for substituting acetophenone, and belongs to the technical field of preparation of fine chemical products. Background technique [0002] α-Bromo-α-acetophenone compounds are one of the important intermediates in organic synthesis. Among them, the bromination reaction of the carbonyl α position of acetophenone has also attracted the attention of many organic workers. The most commonly used method in many synthetic methods that have been reported and practically applied so far is to use bromine water to carry out bromination in different solvents: for example ('Oxidation of non-phenolic β-O-aryl-lignin model dimers catalysed bylignin peroxidase.Comparison with the oxidation induced by potassium12-tungstocobalt(III) ate' Baciocchi, Enrico; Bietti, Massimo; Gerini, Maria Francesca; Lanzalunga, Osvaldo; Mancinelli, Simona; JCSPG...

Claims

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Application Information

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IPC IPC(8): C07C49/807C07C45/63
Inventor 邹新琢高国锐
Owner EAST CHINA NORMAL UNIV
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