阅读说明：本技术 一种制备布南色林中间体（bn-04）的方法 (Method for preparing blonanserin intermediate (BN-04) ) 是由 杨贞皓 段世辉 蒋敏 于 2018-06-06 设计创作，主要内容包括：本发明公开了一种布南色林关键中间体(BN-04)的制备方法,该方法包括如下步骤：4-(4-氟苯基)-5,6,7,8,9,10-六氢环辛烷并吡啶-2(1H)-酮(BN-03)和氯代试剂盐酸在醋酐中于低温下反应,反应毕,减压回收溶剂。降温至50℃以下,加入二氯甲烷和水,用氨水调PH值,分层,无水硫酸钠干燥,减压回收二氯甲烷至净。加入适量乙醇溶解完全,冷却析晶,过滤,得2-氯-4-(4-氟苯基)-5,6,7,8,9,10-六氢环辛烷并吡啶(BN-04)。该方法与现有技术相比,采用了价廉质优的氯化氢做氯代试剂,避免了高温(170℃)反应,减少了杂质的生成,避免了精制过程中的多次重结晶,并且反应溶剂醋酐可以重复使用。可以实现了绿色、安全、环保的现代化生产。(The invention discloses a preparation method of blonanserin key intermediate (BN-04), which comprises the following steps: 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine-2 (1H) -ketone (BN-03) and chlorinated reagent hydrochloric acid react in acetic anhydride at low temperature, and after the reaction is finished, the solvent is recovered under reduced pressure. Cooling to below 50 deg.C, adding dichloromethane and water, adjusting pH with ammonia water, layering, drying with anhydrous sodium sulfate, and recovering dichloromethane under reduced pressure. Adding a proper amount of ethanol to dissolve completely, cooling and crystallizing, and filtering to obtain 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine (BN-04). Compared with the prior art, the method adopts cheap and high-quality hydrogen chloride as a chlorinating reagent, avoids high-temperature (170 ℃) reaction, reduces the generation of impurities, avoids repeated recrystallization in the refining process, and can reuse the reaction solvent acetic anhydride. Can realize green, safe and environment-friendly modern production.)

1. A method for preparing blonanserin intermediate 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine (BN-04), which comprises the following steps:

The preparation method comprises the steps of reacting 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine-2 (1H) -ketone (BN-03) and chlorine hydride serving as a chlorination reagent in acetic anhydride at a low temperature (10-20 ℃), and decompressing and recovering a solvent after the reaction is finished; cooling to below 50 deg.C, adding dichloromethane and water, adjusting pH with ammonia water, stirring, washing, layering, drying with anhydrous sodium sulfate, and recovering dichloromethane under reduced pressure; obtaining off-white solid, namely crude 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine (BN-04);

The method comprises the steps of adding a proper amount of ethanol into the crude BN-04 product obtained in the step of mixing completely, cooling, crystallizing and filtering to obtain white-like to white 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine (BN-04).

2. The process for the preparation of blonanserin intermediate (BN-04) according to claim 1, characterized in that: the chlorinated reagent is hydrogen chloride, and the solvent and dehydrating agent is acetic anhydride; the preparation method of the chlorinated reagent hydrogen chloride comprises the steps of dripping analytically pure hydrochloric acid into acetic anhydride within 0.5-6 h at 0-30 ℃ to prepare the chlorinated reagent hydrogen chloride; preferably, the dripping temperature is 5-15 ℃, and the dripping time is 0.5-2 h.

3. The process for the preparation of blonanserin intermediate (BN-04) according to claim 1, characterized in that: the molar ratio of the compound BN-03 to the chlorinated reagent is 1: 2-1: 10, preferably 1: 3-1: 5.

4. The process for the preparation of blonanserin intermediate (BN-04) according to claim 1, characterized in that: the weight ratio of the compound BN-03 to acetic anhydride is 1: 5-1: 30, preferably 1: 10-1: 20.

5. The process for the preparation of blonanserin intermediate (BN-04) according to claim 1, characterized in that: the reaction conditions in the step are that in a common reactor, the reaction temperature is 0-30 ℃, the reaction time is 1-10 hours, preferably the reaction temperature is 10-20 ℃, and the reaction time is 3-6 hours.

6. The process for the preparation of blonanserin intermediate (BN-04) according to claim 1, characterized in that: in the step, the PH value is adjusted to be 8-9 by ammonia water.

Technical Field

The invention relates to the field of medical chemistry, in particular to a method for preparing blonanserin intermediate 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine (BN-04).

Background

The blonanserin intermediate (BN-04) refers to 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine, and the compound is an important intermediate in the synthesis process of a new atypical antipsychotic blonanserin (blonanserin), and the structure of the compound is shown as the following formula.

。

Blonanserin is a new generation of atypical anti-schizophrenia drug, belongs to 5-hydroxytryptamine receptor antagonist, has a main action mechanism with strong blocking effect on dopamine D2 receptor and 5-hydroxytryptamine receptor, and is mainly used for treating schizophrenia in clinic. The medicine is developed by Sumitomo pharmaceutical corporation of Japan and is marketed in Japan in 1 month of 2008, the main dosage form is tablet, the clinical application is 2mg and 4mg, and the medicine is approved to be marketed as an imported subpackaged variety in China at present.

2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine which is a key intermediate in the synthetic route of blonanserin, and regarding the preparation method of the key intermediate, the prior literature reports mostly use 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine-2 (1H) -ketone (BN-03) as a raw material to react with phenylphosphoryl dichloride at high temperature, after the reaction is finished, the pH value is adjusted, the extraction, the drying and the concentration are carried out, and then the recrystallization with ethanol is carried out. The process operation is complicated, and the solvent consumption is high.

In other documents, phosphorus oxychloride or thionyl chloride is used as a chlorinating reagent, but the reaction time is long and the reaction is incomplete; experiments show that the phosphorus oxychloride can not be completely reacted after being heated, refluxed and reacted for 2 hours.

In chinese patent CN105837504A, the inventor of invar and the like has disclosed an improved method, i.e., 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridopyridine-2 (1H) -ketone (BN-03) and a chlorinated reagent are reacted under certain conditions, after the reaction is finished, the chlorinated reagent is distilled under reduced pressure, the reactant is poured into ice water, the PH value is adjusted by ammonia water, stirring, filtering or centrifuging is performed to obtain a gray solid, and drying is performed to obtain a crude product of 2-chloro 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridopyridine; adding the crude product into ethanol, heating for dissolving, adding a decolorizing agent, filtering while hot, and cooling the filtrate for crystallization. The method improves the yield to 80%. According to the research of the method, the yield can reach 84% when a small amount of materials are fed, but the yield is reduced during amplification, and phenyl phosphoryl dichloride is difficult to concentrate during vacuum concentration and emits a lot of white smoke; hardening easily occurs when transferring black viscous liquid; the materials poured into water are easy to agglomerate and can be broken up only by fast stirring.

In summary, most of the existing preparation methods of blonanserin key intermediate 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine (BN-04) have problems, or have high requirements on equipment, or have complex process, or have long reaction time and incomplete reaction, low yield, or have more waste water, waste liquid and the like, and have great pollution to the environment, so that the existing preparation methods are difficult to meet the requirements of modern industrial production.

Disclosure of Invention

The invention aims to provide a preparation method for preparing blonanserin key intermediate 2-chloro 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine (BN-04) which has completely different reaction conditions, simple operation, safety, environmental protection, excellent and cheap raw materials and is suitable for industrial production, aiming at the defects of the prior art.

See the following equation:

。

In order to achieve the aim, the technical scheme adopted by the invention is that the preparation method of the blonanserin intermediate is sequentially carried out according to the following two steps.

The preparation method comprises the steps of reacting 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridopyridine-2 (1H) -ketone (BN-03) and chlorine hydride serving as a chlorination reagent in acetic anhydride at a low temperature (10-20 ℃), and decompressing and recovering a solvent after the reaction is finished. Cooling to below 50 deg.C, adding dichloromethane and water, adjusting pH with ammonia water, stirring, washing, layering, drying with anhydrous sodium sulfate, and recovering dichloromethane under reduced pressure. An off-white solid, i.e., crude 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydrocyclooctane pyridine (BN-04), was obtained.

The method comprises the steps of adding a proper amount of ethanol into the crude BN-04 product obtained in the step of mixing completely, cooling, crystallizing and filtering to obtain white-like to white 2-chloro-4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine (BN-04).

The chlorination reagent is hydrogen chloride, and the solvent and dehydrating agent is acetic anhydride. The preparation method of the chlorinated reagent is that analytically pure hydrochloric acid is dripped into acetic anhydride within 0.5-6 h at 0-30 ℃ to prepare the chlorinated reagent. Preferably, the dripping temperature is 5-15 ℃, and the dripping time is 0.5-2 h.

The molar ratio of the compound BN-03 to the chlorinated reagent is 1: 2-1: 10, preferably 1: 3-1: 5.

The weight ratio of the compound BN-03 to the acetic anhydride is 1: 5-1: 30, preferably 1: 10-1: 20.

The reaction conditions are that in a common reactor, the reaction temperature is 0-30 ℃, the reaction time is 1-10 hours, and preferably the reaction temperature is 10-20 ℃, and the reaction time is 3-6 hours.

In the step of the first step, the PH value is adjusted to be 8-9 by using ammonia water.

Compared with the prior art, the invention has the following innovation points.

1) The invention uses cheap and high-quality hydrochloric acid as the precursor of the chlorination reagent, thereby not only being more convenient to use and store, but also reducing the production cost.

2) The method uses acetic anhydride as a solvent, is used for dissolving 4- (4-fluorophenyl) -5,6,7,8,9, 10-hexahydro cyclooctane pyridine-2 (1H) -ketone (BN-03), and utilizes the dehydration action to prepare the chlorinated reagent hydrogen chloride, simultaneously ensures that the chlorination reaction is carried out at low temperature, and reduces the generation of reaction byproducts.

3) the reactor used in the invention is a common reactor, and the acetic anhydride, the dichloromethane and the ethanol can be recycled, so that the production cost is reduced.

4) The method has simple reaction steps and convenient post-treatment, avoids the influence of a large amount of waste liquid and the like on the environment, conforms to the characteristic of environmental protection, and meets the requirement of industrial production.

Detailed Description

The following examples are intended to illustrate the invention in detail, but are not intended to limit the invention.