Synthesizing method of 1-benzyl-piperidone hydrochloride

Abstract

The invention discloses a synthesizing method of 1-benzyl-piperidone hydrochloride. The method comprises steps that: (1) 3-hydroxypyridine is added to an organic solvent, and is refluxed under a temperature of 100 to 110 DEG C; benzyl halide is dropped into the solution, and the refluxing reaction is continued for 2 to 4 hours, such that a product A is obtained; (2) the product A is added to an alcohol organic solvent; sodium borohydride is added to the solution under an ice bath; the temperature of the solution is recovered to room temperature; the solution is stirred for 10 to 15 hours; the reaction liquid is quenched by using water; the alcohol organic solvent is removed; the pH value of the solution is regulated to 1-2 by using strong acid; the solution is extracted by using an extractant, and a water phase is preserved; the pH value of the solution is regulated to 13-14 by using an alkali solution, such that a product B is obtained; (3) through a Swerns oxidation reaction, hydroxyl groups in the product B are oxidized into ketone groups; the product is washed; an organic phase is dried, filtered, and condensed; an ethyl acetate hydrochloride solution is added to the product until the pH value is 1-2; the product is stirred and cooled; when solid is completely precipitated, the product is filtered and dried by baking, such that 1-benzyl-piperidone hydrochloride is obtained. The invention is advantaged in low cost and safe operation.

Description

technical field [0001] The present invention relates to the synthetic method of 1-benzyl-3-piperidone hydrochloride. Background technique [0002] 1-Benzyl-3-piperidone hydrochloride is an important intermediate in the synthesis process, so the demand for 1-benzyl-3-piperidone hydrochloride shows a continuous and rapid growth trend. The synthetic route of 1-benzyl-3-piperidone hydrochloride mainly contains following two at present: [0003] (1) Using γ-butyrolactone as the raw material, 1-benzyl-3-piperidone salt is generated through six steps of benzylaminolysis, hydrolysis, esterification, condensation with ethyl bromoacetate, cyclization, and hydrolysis decarboxylation salt, the reaction process is as follows: [0004] [0005] This preparation method was published in China Journal of Pharmaceutical Industry 2004, 35 (7). The advantage is that each step of the reaction is a conventional reaction, without unconventional operations such as high temperature and high pre...

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Problems solved by technology

[0008] This approach is the general technique of producing 1-benzyl-3-piperidone hydrochloride at home and abroad at present, and the producer that uses is more, because it has taken such as precious metal catalysts such as platinum dioxide, platinum carbon, rhodium carbon, greatly The requirement for hydrogen pressure is reduced, usually the reaction can be completed below 5 atmospheres, the requirements for equipment are reduced, and the safety of operation is also improved; however, the cost of noble metal catalysts is very high, and the cost of the entire process route is still difficult to reduce

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