阅读说明：本技术 Pd-i配体的关键中间体的合成方法 (Synthesis method of key intermediate of PD-I ligand ) 是由 黄保华 刘小栋 徐伟 胡新礼 戴建 于 2020-03-31 设计创作，主要内容包括：本发明提供了一种PD-I配体的关键中间体的合成方法,通过化合物2制得中间体5,将其直接溶于溶剂得化合物6；将化合物3和化合物4反应得化合物7；将化合物7回流后,浓缩至干溶解于四氢呋喃中,滴加至含有化合物6和正丁基锂溶液中；反应结束后得化合物8；向含有化合物8的干燥四氢呋喃中加入硼氢化锂,搅拌,淬灭,经萃取等步骤得粗品并纯化得化合物9；将化合物9和二氧化锰混于甲苯中,反应液冷却后过滤,滤液浓缩干后纯化得化合物10；在干燥的四氢呋喃中加入化合物10和Lawesson试剂,加热至回流至反应完成；将反应液浓缩干经纯化得化合物1。本发明路线仅有一步使用了金属催化,且该步骤远离最终化合物,极大降低了药物分子中的金属残留。(The invention provides a synthesis method of a key intermediate of a PD-I ligand, wherein an intermediate 5 is prepared from a compound 2 and directly dissolved in a solvent to obtain a compound 6; reacting the compound 3 with the compound 4 to obtain a compound 7; refluxing the compound 7, concentrating until the compound is dried and dissolved in tetrahydrofuran, and dropwise adding the mixture into a solution containing the compound 6 and n-butyllithium; after the reaction is finished, obtaining a compound 8; adding lithium borohydride into dry tetrahydrofuran containing the compound 8, stirring, quenching, extracting to obtain a crude product, and purifying to obtain a compound 9; mixing the compound 9 and manganese dioxide in toluene, cooling the reaction liquid, filtering, concentrating the filtrate, drying, and purifying to obtain a compound 10; adding the compound 10 and Lawesson reagent into dried tetrahydrofuran, and heating until the reaction is finished; concentrating the reaction solution, drying and purifying to obtain the compound 1. The route of the invention uses metal catalysis in only one step, and the step is far away from the final compound, thus greatly reducing the metal residue in the drug molecule.)

A method for the synthesis of key intermediates of PD-I ligands, characterized in that: the structural formula of the intermediate is shown as the following formula,

the synthesis reaction is as follows:

2. the method of claim 1 for the synthesis of key intermediates of PD-I ligands, characterized in that: comprises the following steps of (a) carrying out,

s1, dissolving the compound 2 in an organic solvent, and hydrogenating under the action of a catalyst; after the reaction is finished, filtering, and concentrating and drying the filtrate to obtain an intermediate 5;

s2, directly dissolving the intermediate 5 in an organic solvent, adding triethylamine, and slowly dropwise adding diphenyl phosphorazide to obtain a compound 6;

s3, dissolving the compound 3 and the compound 4 in ethanol, adding potassium carbonate, replacing nitrogen for 3 times, adding S-Phos under the protection of nitrogen, and heating to 35-45 ℃ for reaction for 10-15 hours;

s4, after the reaction is finished, cooling to room temperature, filtering, concentrating, adding water and dichloromethane, washing an organic phase by using dilute hydrochloric acid, drying by using anhydrous sodium sulfate, and purifying a crude product by using column chromatography to obtain a compound 7;

s5, refluxing the compound 7 prepared in the S4 in thionyl chloride, concentrating the mixture to dryness under reduced pressure, dissolving the mixture in tetrahydrofuran, and dropwise adding the mixture to a solution containing the compound 6 and n-butyllithium at-78 ℃;

s6, after the reaction is finished, returning to room temperature, slowly adding ammonium chloride aqueous solution and dichloromethane, concentrating the organic phase to dryness, and purifying by a silica gel column to obtain a compound 8;

s7, adding lithium borohydride into the dried tetrahydrofuran solution of the compound 8, stirring for 4-6 hours at room temperature, and adding ammonium chloride aqueous solution for quenching; extracting the obtained mixture by dichloromethane, washing by brine, drying by anhydrous sodium sulfate, concentrating under reduced pressure, and purifying the crude product on a silica gel column to obtain a compound 9;

s8, mixing the compound 9 and manganese dioxide in toluene; reacting at room temperature for 4-7 hours, heating to reflux reaction for 2 hours, cooling the reaction liquid, filtering, concentrating the filtrate to dryness, and purifying by silica gel column chromatography to obtain a compound 10;

s9, adding the compound 10 and Lawesson reagent into dried tetrahydrofuran, and heating to reflux under the protection of nitrogen until the reaction is finished;

s10, concentrating the reaction mixture under reduced pressure, and purifying the resulting mixture by silica gel column chromatography to obtain compound 1.

3. A process for the synthesis of key intermediates of PD-I ligands according to claim 2, characterized in that: the system of silica gel column chromatography in S6 and S7 is ethyl acetate/petroleum ether system.

4. A process for the synthesis of key intermediates of PD-I ligands according to claim 2, characterized in that: in the S1, the organic solvent is tetrahydrofuran, and the catalyst is Raney nickel.

5. A process for the synthesis of key intermediates of PD-I ligands according to claim 2, characterized in that: after the reaction of dropwise adding diphenyl phosphorazidate in the step S2 is finished, the solution is concentrated, dichloromethane and water are added, an organic phase is washed by an aqueous solution of sodium bicarbonate, dried by anhydrous sodium sulfate, and finally purified by a silica gel column to obtain a compound 6.

6. A process for the synthesis of key intermediates of PD-I ligands according to claim 2, characterized in that: the temperature of the S3 is increased to 40 ℃ for reaction for 12 hours.

7. A process for the synthesis of key intermediates of PD-I ligands according to claim 2, characterized in that: in S8, compound 9 and manganese dioxide were mixed with toluene and reacted at room temperature for 5 hours.

Technical Field

The invention belongs to the technical field of chemical synthesis, and particularly relates to a synthesis method of a key intermediate of a PD-I ligand.

Background

The immune system plays an important role in controlling and eradicating diseases such as cancer. However, cancer cells can develop new approaches to evade or suppress the immune system to facilitate their growth. One mechanism is to alter the expression of costimulatory and costimulatory molecules on immune cells. Blocking signals from inhibitory immune checkpoints, such as PD-I, has proven to be a promising and effective treatment modality.

Programmed death receptor 1(PD-I), also known as CD279, is a cell surface receptor expressed on activated T cells, natural killer T cells, B cells and macrophages. It acts as an intrinsic negative feedback system preventing activation of T cells, which in turn reduces autoimmunity and promotes self-tolerance. In addition, PD-1 plays a key role in suppressing its response to antigen-specific T cells in diseases such as cancer and viral infection.

Several lines of evidence in preclinical animal studies suggest that PD-I and its ligands negatively regulate immune responses. PD-I deficient mice have been shown to develop lupus-like adrenalitis and dilated cardiomyopathy. Using the LCMV model of chronic infection, it was shown that PD-I/PD-LI interactions inhibit activation, expansion and acquisition of effector functions of virus-specific CD8T cells. Together, these data support the development of a therapeutic approach to prevent the PD-I mediated inhibitory signaling cascade to enhance the enhancer 'rescue' T cell response. Therefore, new compounds are needed to prevent PD-I/PD-LI proteins/proteins from interacting.

Formula 1 is a key intermediate of compounds used to prevent PD-I/PD-LI protein/protein interactions. The intermediate can be derived to obtain a plurality of candidate drugs for PD-I/PD-LI protein/protein interaction.

The existing synthetic method has complicated steps, and the final product possibly has metal substance residues due to multiple metal catalysis in the reaction, so that the purity of the final product is not enough, and the subsequent preparation of the medicine is influenced.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a synthesis method of a key intermediate of a PD-I ligand.

The purpose of the invention is realized by the following technical scheme:

a synthesis method of a key intermediate of a PD-I ligand is disclosed, wherein the intermediate has a structural formula shown in the specification,

the synthesis reaction is as follows:

preferably, the synthesis method of the key intermediate of the PD-I ligand comprises the following steps,

s1, dissolving the compound 2 in an organic solvent, and hydrogenating under the action of a catalyst; after the reaction is finished, filtering, and concentrating and drying the filtrate to obtain an intermediate 5;

s2, directly dissolving the intermediate 5 in an organic solvent, adding triethylamine, and slowly dropwise adding diphenyl phosphorazide to obtain a compound 6;

s3, dissolving the compound 3 and the compound 4 in ethanol, adding potassium carbonate, replacing nitrogen for 3 times, adding S-Phos under the protection of nitrogen, and heating to 35-45 ℃ for reaction for 10-15 hours;

s4, after the reaction is finished, cooling to room temperature, filtering, concentrating, adding water and dichloromethane, washing an organic phase by using dilute hydrochloric acid, drying by using anhydrous sodium sulfate, and purifying a crude product by using column chromatography to obtain a compound 7;

s5, refluxing the compound 7 prepared in the S4 in thionyl chloride, concentrating the mixture to dryness under reduced pressure, dissolving the mixture in tetrahydrofuran, and dropwise adding the mixture to a solution containing the compound 6 and n-butyllithium at-78 ℃;

s6, after the reaction is finished, returning to room temperature, slowly adding ammonium chloride aqueous solution and dichloromethane, concentrating the organic phase to dryness, and purifying by a silica gel column to obtain a compound 8;

s7, adding lithium borohydride into the dried tetrahydrofuran solution of the compound 8, stirring for 4-6 hours at room temperature, and adding ammonium chloride aqueous solution for quenching; extracting the obtained mixture by dichloromethane, washing by brine, drying by anhydrous sodium sulfate, concentrating under reduced pressure, and purifying the crude product on a silica gel column to obtain a compound 9;

s8, mixing the compound 9 and manganese dioxide in toluene; reacting at room temperature for 4-7 hours, heating to reflux reaction for 2 hours, cooling the reaction liquid, filtering, concentrating the filtrate to dryness, and purifying by silica gel column chromatography to obtain a compound 10;

s9, adding the compound 10 and Lawesson reagent into dried tetrahydrofuran, and heating to reflux under the protection of nitrogen until the reaction is finished;

s10, concentrating the reaction mixture under reduced pressure, and purifying the resulting mixture by silica gel column chromatography to obtain compound 1.

Preferably, the system of silica gel column chromatography in S6 and S7 is an ethyl acetate/petroleum ether system.

Preferably, the organic solvent in S1 is tetrahydrofuran, and the catalyst is raney nickel.

Preferably, after the reaction of S2 by adding diphenyl phosphorazidate dropwise, the solution is concentrated, dichloromethane and water are added, the organic phase is washed with an aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, and finally purified by silica gel column to obtain compound 6.

Preferably, the temperature in the S3 is increased to 40 ℃ for reaction for 12 hours.

Preferably, compound 9 and manganese dioxide are mixed in toluene in S8 and reacted at room temperature for 5 hours.

The invention has the beneficial effects that: the route of the invention uses metal catalysis in only one step, and the step is far away from the final compound, thus greatly reducing the metal residue in the drug molecule.

Detailed Description

The technical scheme of the invention is specifically illustrated by combining the following embodiments, and the invention discloses a synthesis method of a key intermediate of a PD-I ligand.

Example 1

Preparation of compound 6, the reaction is shown below:

2.43g of Compound 2 are dissolved in tetrahydrofuran and hydrogenated under Raney Ni catalysis. After the reaction is finished, filtering, concentrating and drying the filtrate to obtain an intermediate 5, and directly putting the intermediate 5 into the next reaction. The intermediate 5 was dissolved in tetrahydrofuran, triethylamine was added, and diphenyl phosphorazidate (DPPA) was slowly added dropwise. After completion of the reaction, the solution was concentrated, methylene chloride and water were added, and the organic phase was washed with an aqueous sodium hydrogencarbonate solution and dried over anhydrous sodium sulfate. Final silica gel column purification afforded compound 6, 1.74g, 72% yield.

Example 2

The preparation of compound 7, the reaction formula of which is shown below,

1.2eq of Compound 3 and 340mg of Compound 4 are dissolved in 100mL of ethanol, 5 equivalents of potassium carbonate are added, nitrogen is replaced 3 times, 2 mol% S-Phos is added under nitrogen protection, and the mixture is heated to 40 ℃ for reaction for 12 hours. After the reaction is finished, cooling to room temperature, filtering, concentrating, adding water and dichloromethane, washing an organic phase by using dilute hydrochloric acid, and drying by using anhydrous sodium sulfate. The crude product was purified by column chromatography to give compound 7, 355mg, 84% yield.

Example 3

Preparation of compound 8, the reaction is shown below:

340mg of Compound 7 was refluxed in 50mL of thionyl chloride and then concentrated to dryness under reduced pressure. The above mixture was dissolved in tetrahydrofuran, and it was added dropwise to a solution containing 1 equivalent of compound 6 and 1.2 equivalents of n-butyllithium at-78 ℃. After the reaction was completed, the temperature was returned to room temperature, and an aqueous ammonium chloride solution and dichloromethane were slowly added. The organic phase was concentrated to dryness and purified by silica gel column to give compound 8, 350mg, 83% yield.

Example 4

Preparation of compound (formula 9) having the reaction formula:

to a dry tetrahydrofuran solution (20mL) containing the compound (formula 8) (436mg) was added lithium borohydride (3 equiv.), and after stirring at room temperature for 5 hours, aqueous ammonium chloride was added for quenching. The resulting mixture was extracted with dichloromethane, washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified on silica gel column to give compound 9, 383mg, 93% yield.

Example 5

Preparation of compound 10, the reaction scheme is shown below:

205mg of compound 9 and fresh 10 equivalents of manganese dioxide are mixed in 10mL of toluene. After 5 hours at room temperature, the reaction mixture was heated to reflux for 2 hours. The reaction solution was cooled and filtered, and the filtrate was concentrated to dryness and purified by silica gel column chromatography (ethyl acetate/petroleum ether) to give 10, 150mg, yield 73%.

Example 6

Preparation of compound 1, the reaction is shown below:

to 5mL of dry tetrahydrofuran were added 204mg of Compound 10 and 2 equivalents of Lawesson's reagent. Heat to reflux under nitrogen blanket until reaction is complete. The reaction solution was then completely concentrated to dryness under reduced pressure, and the resulting mixture was purified by silica gel column chromatography (ethyl acetate/petroleum ether) to give compound 1, 162mg, 79.8%.

There are, of course, many other specific embodiments of the invention and these are not to be considered as limiting. All technical solutions formed by using equivalent substitutions or equivalent transformations fall within the scope of the claimed invention.