The invention discloses a preparation method of N-monosubstituted homopiperazines The compounds can be widely used in the fields of medicines, pesticides, surfactants, energetic materials and the like The invention adopts a four-step method to prepare the N-monosubstituted homopiperazines The synthesis method disclosed by the invention has the advantages of cheap and accessible raw materials, simple synthesis technique, mild reaction conditions, high yield, simple reaction operation and wide application range, and satisfies the requirements for industrial production of products

Preparation method of N-monosubstituted homopiperazines

The invention discloses an N-methylhomopiperazine synthesis method. The N-methylhomopiperazine synthesis method comprises the following synthesis steps: (1) taking N-methylpiperidone as the raw material, enabling the N-methylpiperidone and hydroxylamine hydrochloride to have a beckmann rearrangement reaction at the appropriate temperature under the action of a Lewis acid catalyst to generate amide; (2) implementing a reduction reaction on the amide synthesized in the step (1) under the appropriate conditions of a reducing agent, a catalyst, the temperature and a solvent, and obtaining the N-methylhomopiperazine. The N-methylhomopiperazine synthesis method uses the cheap easy-to-get N-methylpiperidone as the raw material, the N-methylpiperidone and the hydroxylamine hydrochloride have the beckmann rearrangement reaction under the catalytic action of the Lewis acid to generate the amide, the amide is processed through a compound reduction system to obtain the N-methylhomopiperazine. Thepurity of a target product obtained by using the process is high, the reaction condition is mild, the yield is good, the operation is simple and convenient, the production cost is low, and the synthesis method is suitable for amplifying production.

N-methylhomopiperazine synthesis method

PURPOSE:To obtain the titled compound useful as an intermediate for pharmaceuticals, in high yield and purity, by catalytically reducing N-methyl-2(or 7)-homopiperazinone in the presence of a dioxane solvent using a specific catalyst and cooling the reaction system immediately after the completion of reduction. CONSTITUTION:N-methyl-2(or 7)-homopiperazinone is used as a raw material and subjected to catalytic reduction usually at 100-350 deg.C, preferably 150-300 deg.C under 5-500kg/cm , preferably 30-150kg/cm pressure in a dioxane solvent in the presence of a copper-chromium catalyst. Immediately after the completion of the reduction, the reaction system is cooled to obtain the objective compound. The cooling is carried out e.g. by using a continuous reduction reactor, by taking the reaction system out of a batch autoclave reactor in the form of vapor or liquid, etc., immediately after the reduction, etc. A commercially available low-cost copper-chromium catalyst can be used as it is as the above catalyst.

Fujii Shigeo

Papers

Production of n-methylhomopiperazine