Novel method for synthesizing cyclopropyl bromide

A technology of cyclopropyl bromide and a new method, which is applied in the field of fine chemical intermediates, can solve problems such as environmental damage, and achieve the effects of avoiding pollution, convenient operation, and simple synthesis and separation

Active Publication Date: 2015-09-09
CANGZHOU PURUI DONGFANG SCI & TECH +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The mercury oxide used in this method is a highly toxic chemical, and the m

Method used

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  • Novel method for synthesizing cyclopropyl bromide

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Experimental program
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Embodiment 1

[0020] Synthesis of cyclopropionyl imidazole:

[0021] In a 250mL three-necked flask, add 150ml of dichloromethane and 34.4 grams (0.4 moles) of cyclopropanecarboxylic acid in sequence. After stirring evenly, add 64.9 grams (0.4 moles) of carbonyldiimidazole in 4-6 batches. over 30°C. After the addition was completed, the reaction was stirred at room temperature for 1 hour, and the reaction was basically complete as detected by TLC. Saturated ammonium chloride was added, and the aqueous layer was extracted once with 50 ml of dichloromethane. The organic layers were combined, washed with saturated brine, dried over anhydrous magnesium sulfate, and evaporated to dryness to obtain liquid cyclopropionyl imidazole. This compound can be directly used in the next reaction.

[0022] Synthesis of cyclopropyl bromide:

[0023] Under nitrogen protection, in a 500mL three-necked flask, add 250ml of 1,2-dichloroethane and 79.3g (0.4mol) of trichlorobromomethane into the above ...

Embodiment 2

[0025] Synthesis of cyclopropionyl imidazole:

[0026] In a 250mL three-necked flask, add 150ml of tetrahydrofuran and 34.4g (0.4mol) of cyclopropanecarboxylic acid in sequence. After stirring evenly, add 71.3g (0.44mol) of carbonyldiimidazole in 4-6 batches. During the addition, the temperature is controlled not to exceed 30 ℃. After the addition was completed, the reaction was stirred at room temperature for 1 hour, and TLC detected that the reaction was complete. After rotary evaporation of the solvent, saturated ammonium chloride and 1,2-dichloroethane were added, washed with saturated brine, dried over anhydrous magnesium sulfate, and filtered to obtain a liquid cyclopropionyl imidazole 1,2-dichloroethane solution. This compound can be directly used in the next reaction.

[0027] Synthesis of cyclopropyl bromide:

[0028] Under the protection of nitrogen, add 220 ml of 1,2-dichloroethane and 87.2 g (0.44 mole) of trichlorobromomethane to the above-mentioned r...

Embodiment 3

[0030] Synthesis of cyclopropionyl imidazole:

[0031] In a 250mL three-necked flask, add 150ml of acetonitrile and 34.4g (0.4mol) of cyclopropanecarboxylic acid in sequence. After stirring evenly, add 64.9g (0.4mol) of carbonyldiimidazole in 4-6 batches. During the addition process, control the temperature not to exceed 30 ℃. After the addition was completed, the reaction was stirred at room temperature for 1 hour, and TLC detected that the reaction was complete. Saturated ammonium chloride was added, and the aqueous layer was extracted once with 50 ml of dichloromethane. The organic layers were combined, washed with saturated brine, dried over anhydrous magnesium sulfate, and evaporated to dryness to obtain liquid cyclopropionyl imidazole. This compound can be directly used in the next reaction.

[0032] Synthesis of cyclopropyl bromide:

[0033] Under nitrogen protection, add 180 ml of toluene and 95.2 g (0.48 moles) of bromotrichloromethane to the above reacti...

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Abstract

The invention relates to a novel method for synthesizing cyclopropyl bromide. The novel method comprises the following steps: carrying out a reaction between cyclopropyl carboxylic acid and carbonyl diimidazole to generate cyclopropyl acyl imidazole, then mixing the intermediate with bromo-trichloromethane, adding an oxidizing agent slowly under the condition that the temperature is kept to be 10 to 140 DEG C for a free radical deacidification bromination reaction, so as to obtain a cyclopropyl bromide crude product, and carrying out simple normal pressure rectification to obtain a product of which the purity is 99 percent or higher. The novel method has the advantages that the reaction conditions are mild; the used reagents are conventional, cheap and high in availability; mercuric oxide, which is a highly toxic product, is not used any more; the novel method is suitable for industrial scale-up production.

Description

technical field [0001] The invention relates to a new method for synthesizing cyclopropyl bromide, which belongs to the field of fine chemical intermediates. Background technique [0002] Cyclopropyl bromide is an important chemical and pharmaceutical synthesis intermediate, which can be used to synthesize cyclopropylboronic acid for Suzuki coupling reaction and fluoroquinolone antibacterial drugs such as ciprofloxacin. [0003] At present, the existing synthetic methods basically start from cyclopropanecarboxylic acid, react with red mercury oxide in 1,1,2,2-tetrachloroethane or carbon tetrachloride, and obtain cyclopropyl bromide after decarboxylation and bromination . The mercury oxide used in this method is a highly toxic chemical, and the mercury pollution produced has a great destructive effect on the environment. Contents of the invention [0004] In order to overcome the defect of above-mentioned synthetic method, the present invention starts from cyclopropyl for...

Claims

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Application Information

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IPC IPC(8): C07C23/04C07C17/363
Inventor 冷延国郭世学李娟娟
Owner CANGZHOU PURUI DONGFANG SCI & TECH
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