Chemosynthesis method of 4-bromomethyl-5-methyl-1,3-dioxy heterocyclic pentene-2-ketone

A technology of dioxole and bromomethyl, which is applied in the field of chemical synthesis of 4-bromomethyl-5-methyl-1,3-dioxol-2-one, can solve bromine Eliminate problems such as poor substitution selectivity, low reaction yield, and high toxicity of liquid bromine, and achieve the effects of less three wastes, simple operation, and safe and reliable production

Active Publication Date: 2008-08-27
ZHEJIANG UNIV OF TECH +1
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  • Abstract
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AI Technical Summary

Problems solved by technology

Although the bromine bromination method has been widely used in industry, the selectivity of bromine to the allyl position is far worse than that of NBS, the reaction yield is low, and the toxicity of liquid bromine is too high, so the application also has great safety question
Therefore, there are certain limitations in industrial application.

Method used

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  • Chemosynthesis method of 4-bromomethyl-5-methyl-1,3-dioxy heterocyclic pentene-2-ketone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] The molar ratio of the feed material is DMDO:NBS is 1:1, the organic solvent is carbon tetrachloride; the initiator is azobisisobutyronitrile, and its dosage is about 5% of the DMDO mass; the reaction time is 15 minutes.

[0021] Add 500ml of carbon tetrachloride and 34.2g of DMDO to a 1L four-neck flask equipped with a mechanical stirrer, a reflux condenser and a thermometer, then heat up and reflux. After reflux, add 1.71g (5%) initiator azobisisobutyronitrile (AIBN) and 53.4g N-bromosuccinimide (NBS), cool after reacting for 15 minutes, and the reaction liquid washes three times (3 * 500ml ), liquid separation, the organic layer was taken and dried with anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a crude product. After rectification of the crude product, 48.6 g of the product 4-bromomethyl-5-methyl-1,3-dioxol-2-one was obtained, with a yield of 84% and a purity of 87.6%.

[0022] Structural characteri...

Embodiment 2

[0025] The molar ratio of the feed material is DMDO:NBS is 1:0.9, the organic solvent is carbon tetrachloride; the initiator is azobisisobutyronitrile, the dosage is about 8% of DMDO; the reaction time is 15 minutes.

[0026] Add 500ml of carbon tetrachloride and 34.2g of DMDO to a 1L four-neck flask equipped with a mechanical stirrer, a reflux condenser and a thermometer, then heat up and reflux. After reflux, add 2.74g (8%) initiator azobisisobutyronitrile (AIBN) and 48.1g N-bromosuccinimide (NBS), cool after reacting for 15 minutes, and the reaction solution is washed three times with water (3 × 500ml ), liquid separation, the organic layer was taken and dried with anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a crude product. After rectification of the crude product, 43.6 g of the product 4-bromomethyl-5-methyl-1,3-dioxol-2-one was obtained, with a yield of 75.3% and a purity of 87.1%.

Embodiment 3

[0028] The molar ratio of the feed material is DMDO:NBS is 1:1.1, the organic solvent is carbon tetrachloride; the initiator is azobisisobutyronitrile, and the dosage thereof is about 10% of DMDO; the reaction time is 15 minutes.

[0029] Add 500ml of carbon tetrachloride and 34.2g of DMDO to a 1L four-neck flask equipped with a mechanical stirrer, a reflux condenser and a thermometer, and heat up to reflux. After reflux, add 3.42g (10%) initiator azobisisobutyronitrile (AIBN) and 58.7g N-bromosuccinimide (NBS), cool after reacting for 15 minutes, and the reaction solution is washed three times with water (3 * 500ml ), liquid separation, the organic layer was taken and dried with anhydrous magnesium sulfate, filtered, and the filtrate was rotary evaporated to remove the solvent to obtain a crude product. After rectification of the crude product, 42.2 g of the product 4-bromomethyl-5-methyl-1,3-dioxol-2-one was obtained, with a yield of 72.9% and a purity of 86.9%.

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Abstract

The invention provides a chemical synthesis method of 4-bromomethyl-5-methyl-1, 3-dioxa cyclopentene-2-ketone, which comprises using 4, 5-dimethyl-1, 3-dioxa cyclopentene-2-ketone as raw material and uses N-bromosuccinimide as bromination agent to be reacted in the presence of initiator and in organic solvent, separating and purifying the reaction liquor after the reaction, to obtain 4-bromomethyl-5-methyl-1, 3-dioxa cyclopentene-2-ketone. The chemical synthesis method of 4-bromomethyl-5-methyl-1, 3-dioxa cyclopentene-2-ketone has the advantages of reasonable process conditions, reliable and safe production, simple operation, little discharge of three wastes and benefit for industrial production.

Description

(1) Technical field [0001] The invention relates to a chemical synthesis method of 4-bromomethyl-5-methyl-1,3-dioxol-2-one. (2) Background technology [0002] 4-Bromomethyl-5-methyl-1,3-dioxol-2-one is mainly used in the synthesis of new semi-synthetic antibiotics, for example, in the synthesis of semi-synthetic penicillin-lenampicillin hydrochloride. [0003] The existing main method of chemically synthesizing 4-bromomethyl-5-methyl-1,3-dioxol-2-one is obtained by bromine bromination reaction, such as JP 58 152879, 1983, US 4428806, Chem.Pharm.Bull.1984, 32, 6, 2241-2248, etc. Although the bromine bromination method has been widely used in industry, the selectivity of bromine to the allyl position is far worse than that of NBS, the reaction yield is low, and the liquid bromine is too toxic, so the application also has great safety question. Therefore, there are certain limitations in industrial application. (3) Contents of the invention [0004] The purpose of the pre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D317/40
Inventor 俞传明苏为科谢媛媛何人宝王莺妹钟建新
Owner ZHEJIANG UNIV OF TECH
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