Method for preparing 5-ethyl-5-(1-methylbutyl)malonylurea

A technology of methyl butyl and malonyl urea, which is applied in the field of drug synthesis, can solve the problems of many by-products, long reaction time, and high cost, and achieve the effects of mild reaction conditions, simple post-processing, and low production cost
CN105541731AInactive Publication Date: 2016-05-04SHANDONG XINHUA PHARMA CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
SHANDONG XINHUA PHARMA CO LTD
Publication Date
2016-05-04
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention belongs to the technical field of drug synthesis and particularly relates to a method for preparing 5-ethyl-5-(1-methylbutyl)malonylurea. A mixture which is obtained after ethyl-propanedioic acid diethyl ester (III) reacts with an alcohol solution of sodium ethoxide reacts with methanesulfonic acid (2-pentyl) ester under the condition that toluene exists, and an ethyl-(1-methylbutyl) diethyl malonate compound (II) is obtained through rectification; the compound (II) reacts with urea under the condition that a methanol solution of sodium methoxide exists, and a fine 5-ethyl-5-(1-methylbutyl)malonylurea (I) product is obtained through hydrochloric acid acidizing and re-crystallization. The technology is stable, reaction conditions are moderate, control is easy, the obtained product is high in purity and high in yield, the conversion rate nearly reaches 100%, post-processing is easy and convenient, energy consumption is low, three wastes are few, mother liquor can be continuously used, production cost is low, and the method is suitable for industrial production.
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Description

technical field

[0001] The invention belongs to the technical field of medicine synthesis, and in particular relates to a preparation method of 5-ethyl-5-(1-methylbutyl)malonylurea. Background technique

[0002] 5-Ethyl-5-(1-methylbutyl)malonylurea (I) is mainly used for sedation, hypnosis, administration before anesthesia and anticonvulsant.

[0003] Existing preparation technology, its step is that diethyl ethyl malonate reacts with 2-bromopentane in the alcoholic solution of sodium ethylate to obtain ethyl-(1-methylbutyl) diethyl malonate compound (II), the latter reacts with urea in an alcoholic solution of sodium ethoxide to obtain compound (I). The 2-bromopentane used in this process contains the isomer 3-bromopentane. Due to the unavoidable simultaneous production of isomer 3-bromopentane during the preparation of 2-bromopentane, the physical and chemical properties of 2-bromopentane and 3-bromopentane are almost completely similar, and the difference in boiling poi...

Claims

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