Process for preparing N-benzyl piperazine

Abstract

The invention relates to a process for preparing N-benzyl piperazine, that is, piperazine reacts with halogenated benzyl to produce N-N-benzyl piperazine in the presence of catalyst. The preparation process comprises the following steps: solving the piperazine in the solvent, introducing nitrogenous amine salt as catalyst, adding dropwise halogenated benzyl at 0-100C. and reacting with piperazine, keeping temperature for 0.5-24 hours after reaction, vacuum distillation for removing solvent, adding alkali to strongly alkaline, extraction by extractant, distillation, and rectification to produce product with purity over 99% and yield above 95%.

Description

technical field

[0001] The invention relates to a preparation method of a pharmaceutical intermediate, in particular N-benzylpiperidine, an intermediate of pharmaceutical products such as rifamycin for treating tuberculosis infection, dopamine for treating and preventing neuropsychological diseases, and trimetazidine for relaxing blood vessels. The preparation method of oxazine. Background technique

[0002] N-benzyl piperazine (N-benzyl piperazine) is an important nitrogen-containing heterocyclic compound and a pharmaceutical intermediate. Its derivatives can be made into a variety of pharmaceutical products, such as rifamycin for the treatment of tuberculosis infection , dopamine for the treatment and prevention of neuropsychological diseases, trimetazidine for dilating blood vessels, and antiallergic drug pyridazinone, etc. The current preparation method of N-benzylpiperazine is formed by condensation of piperazine and benzyl halide under the action of a catalyst. Commo...

Examples

Embodiment approach

[0019] In a 500ml reaction bottle, drop 25.8g (0.3mol) of piperazine and 100ml of solvent anhydrous methanol, stir and dissolve, then drop into the catalyst aniline hydrochloride, heat up to 50 degrees, drop 38g (0.3mol) of benzyl chloride, about Add dropwise in half an hour. Keep the temperature at 50°C for 3 hours, cool to normal temperature, reduce the pressure to 15mmhg, and evaporate to remove the solvent methanol. Then add NaOH solution, adjust the pH value to 13, and extract twice with ethyl acetate, each with 50 ml of ethyl acetate. The extract was distilled under normal pressure, reduced to 2.5 mmhg, and the fraction at 120-124 ° C was collected by distillation to finally obtain 50.5 g of the target product N-benzylpiperazine with a yield of 95.5% and a purity of 99.2%.

technical field

[0001] The invention relates to a preparation method of a pharmaceutical intermediate, in particular N-benzylpiperidine, an intermediate of pharmaceutical products such as rifamycin for treating tuberculosis infection, dopamine for treating and preventing neuropsychological diseases, and trimetazidine for relaxing blood vessels. The preparation method of oxazine. Background technique

[0002] N-benzyl piperazine (N-benzyl piperazine) is an important nitrogen-containing heterocyclic compound and a pharmaceutical intermediate. Its derivatives can be made into a variety of pharmaceutical products, such as rifamycin for the treatment of tuberculosis infection , dopamine for the treatment and prevention of neuropsychological diseases, trimetazidine for dilating blood vessels, and antiallergic drug pyridazinone, etc. The current preparation method of N-benzylpiperazine is formed by condensation of piperazine and benzyl halide under the action of a catalyst. Commo...

Examples

Embodiment approach

[0019] In a 500ml reaction bottle, drop 25.8g (0.3mol) of piperazine and 100ml of solvent anhydrous methanol, stir and dissolve, then drop into the catalyst aniline hydrochloride, heat up to 50 degrees, drop 38g (0.3mol) of benzyl chloride, about Add dropwise in half an hour. Keep the temperature at 50°C for 3 hours, cool to normal temperature, reduce the pressure to 15mmhg, and evaporate to remove the solvent methanol. Then add NaOH solution, adjust the pH value to 13, and extract twice with ethyl acetate, each with 50 ml of ethyl acetate. The extract was distilled under normal pressure, reduced to 2.5 mmhg, and the fraction at 120-124 ° C was collected by distillation to finally obtain 50.5 g of the target product N-benzylpiperazine with a yield of 95.5% and a purity of 99.2%.

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