阅读说明：本技术 一种催化制备二氢[1，2，4]***并[1，5-a]嘧啶类衍生物的方法 (method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives through catalysis ) 是由 卢华 沈建忠 于 2019-08-30 设计创作，主要内容包括：本发明公开了一种催化制备二氢[1,2,4]三唑并[1,5-a]嘧啶类衍生物的方法,属于医药化工技术领域。本发明的一种催化制备二氢[1,2,4]三唑并[1,5-a]嘧啶类衍生物的方法,是以芳香醛、β-酮酸酯和3-氨基-1,2,4-三唑为反应原料,以乙醇-二甲基甲酰胺水溶液为反应溶剂,在磁性纳米磺酸催化剂的催化作用下来反应制备二氢[1,2,4]三唑并[1,5-a]嘧啶类衍生物的。该方法具有产品收率高、制备工艺简单、催化剂循环使用次数多、反应原料利用率高以及易于工业化大规模生产等优点。(The invention discloses a method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives by catalysis, and belongs to the technical field of pharmaceutical chemicals. The invention relates to a method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives by catalysis, which takes aromatic aldehyde, beta-keto ester and 3-amino-1, 2, 4-triazole as reaction raw materials, takes ethanol-dimethylformamide aqueous solution as a reaction solvent, and reacts under the catalysis of a magnetic nano sulfonic acid catalyst to prepare the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives. The method has the advantages of high product yield, simple preparation process, more times of catalyst recycling, high utilization rate of reaction raw materials, easy industrial large-scale production and the like.)

1. A method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives in a catalytic manner, which is characterized in that: the method takes aromatic aldehyde, beta-keto ester and 3-amino-1, 2, 4-triazole as reaction raw materials, and dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives are prepared by reaction under the catalysis of a magnetic nano sulfonic acid catalyst.

2. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 1, wherein: the preparation reaction takes ethanol-dimethylformamide aqueous solution as a reaction solvent.

3. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 2, wherein: the volume ratio of ethanol, dimethylformamide and water in the reaction solvent, V ethanol: v dimethylformamide: v water (5-8): 2: 1.

4. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 2, wherein: the volume amount of the reaction solvent in milliliters is 5-9 times of the amount of the aromatic aldehyde in millimoles.

5. the process for the catalytic preparation of dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative according to any one of claims 1 to 4, wherein: the mass of the magnetic nano sulfonic acid catalyst in grams is 12-20% of the amount of aromatic aldehyde in millimoles, and the molar ratio of the aromatic aldehyde, the beta-keto ester and the 3-amino-1, 2, 4-triazole as reaction raw materials is 1: 1: 1.

6. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to any one of claims 1-4, which is characterized in that the specific preparation process comprises the following steps: adding aromatic aldehyde, beta-keto ester, 3-amino-1, 2, 4-triazole and a magnetic nano sulfonic acid catalyst into a reaction solvent respectively, stirring uniformly, heating to 78-86 ℃ for reaction, and preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative.

7. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 6, wherein: the reaction pressure is one atmosphere, and the reaction time is 85-146 min.

8. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 6, wherein: after the reaction is finished, the magnetic nano sulfonic acid catalyst is adsorbed by a magnet when the reaction solution is hot, the residual reaction solution is cooled to room temperature, the precipitated solid is crushed, kept stand and filtered, and the obtained filter residue is washed and dried in vacuum to obtain the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative; directly putting the adsorbed catalyst into the filtrate after suction filtration without any treatment, and directly adding the reaction raw materials for next reaction.

9. the method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 6, wherein: the aromatic aldehyde is any one of p-nitrobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-fluorobenzaldehyde, o-chlorobenzaldehyde and m-fluorobenzaldehyde.

10. The method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives under catalysis according to claim 6, wherein: the beta-keto ester is any one of methyl propionylacetate and ethyl acetoacetate.

Technical Field

the invention belongs to the technical field of pharmaceutical chemicals, and particularly relates to a catalytic preparation method of a dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative serving as a medical intermediate.

Background

The pyrimidine compound is a six-membered heterocyclic compound containing two nitrogen atoms in a molecular structure, is widely applied in the fields of medicines, pesticides, dyes and the like, and can also be used as a precursor for developing anticancer drugs. Wherein, the dihydropyrimidine is an indispensable pyrimidine compound, the derivative thereof has potential pharmacological activity and biological activity, can be used as an inhibitor of the activity of vascular endothelial cell growth factor receptor 2 and TIE-2, and also has the activity of resisting tumor cells. In addition, the compound containing the triazole structure is also an important medicine, pesticide and dye intermediate, and particularly in the field of medicine, the triazole pharmacophore has lower toxicity than the imidazole and shows various biological activities, such as antifungal activity, antibacterial activity, antituberculosis activity, antiviral activity and the like. Therefore, the preparation of dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives containing triazole and pyrimidine structures is one of the hot spots and the important points of research and development of medical intermediates in recent years.

At present, the synthesis methods of dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives are divided into a plurality of methods according to different reaction raw materials and catalysts, wherein the selection of the catalyst comprises traditional Bronsted acid such as p-toluenesulfonic acid, acetic acid, sulfamic acid and the like, but the catalysts cannot be recycled, and a large amount of waste acid is brought, so that the environment is harmed.

Based on this, some researchers have used solid acid instead, such as Albalajiang. keiki wood, etc. used solid acidic ion exchange resin Amberlyst-15 as catalyst, a series of dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives are synthesized by taking ethanol as a reaction solvent and aromatic aldehyde, beta-keto ester and 3-amino-1, 2, 4-triazole as raw materials through a three-component one-pot method, the catalyst Amberlyst-15 can be recycled for 4 times, and the catalytic activity is not obviously reduced (the one-pot method for synthesizing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine and dihydrobenzo [4, 5] imidazo [1, 2-a ] pyrimidine derivatives under the catalysis of the Amberlyst-15 is adopted to synthesize [ J ] and the organic chemistry is 2019, 39: 1945-1952). However, the synthesis method still has the following defects: 1. the preparation of the catalyst is relatively complicated, and the recycling frequency is low; 2. the reaction solvent ethanol can not be recycled, so that the economic benefit is low; 3. the purification process of the product is relatively complex, and the yield is low; 4. the catalytic efficiency is low and the reaction time is long.

Disclosure of Invention

1. Problems to be solved

The invention aims to overcome the defects of low catalytic efficiency, long reaction time, poor recycling performance and the like of a catalyst in the existing preparation process of dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives, and provides a method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives through catalysis. The method for preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives by using the magnetic nano sulfonic acid as the catalyst has the advantages of high efficiency, high product yield, multiple times of recycling the catalyst, simple preparation process and easy industrial large-scale production.

2. Technical scheme

In order to solve the problems, the technical scheme adopted by the invention is as follows:

The invention relates to a method for preparing dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives by catalysis, which takes aromatic aldehyde, beta-keto ester and 3-amino-1, 2, 4-triazole as reaction raw materials, takes ethanol-dimethylformamide aqueous solution as a reaction solvent, and reacts under the catalysis of a magnetic nano sulfonic acid catalyst to prepare the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivatives, wherein the chemical reaction formula is as follows:

Wherein the molar ratio of the aromatic aldehyde, the beta-keto ester and the 3-amino-1, 2, 4-triazole in the reaction is 1: 1: the mass of the magnetic nano sulfonic acid catalyst in grams is 12-20% of the amount of the aromatic aldehyde in millimoles, the reaction solvent ethanol-dimethylformamide aqueous solution (V (ethanol): V (dimethylformamide): V (water): 5-8): 2: 1) is 5-9 times of the amount of the aromatic aldehyde in millimoles in volume in milliliters, the reaction pressure is one atmosphere, the reaction temperature is 78-86 ℃, and the reaction time is 85-146 min.

And (3) adsorbing the magnetic nano sulfonic acid catalyst with a magnet when the reaction is finished, cooling the residual reaction liquid to room temperature, separating out a large amount of solids, crushing the solids, standing, performing suction filtration, washing the obtained filter residue with ethanol, and performing vacuum drying to obtain the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative. The adsorbed catalyst is put into the filtrate after suction filtration without any treatment, and then the catalyst can be directly added into the reaction raw materials for the next reaction.

The aromatic aldehyde used in the invention is any one of p-nitrobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-fluorobenzaldehyde, o-chlorobenzaldehyde and m-fluorobenzaldehyde, and the beta-keto ester is any one of methyl propionylacetate and ethyl acetoacetate. The preparation method of the magnetic nano sulfonic acid catalyst is disclosed in the related literature (preparation of magnetic nano sulfonic acid and catalyzed organic chemical reaction [ D ], university of Hebei university, 2015).

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

(1) The method for preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative by catalysis takes the aromatic aldehyde, the beta-keto ester and the 3-amino-1, 2, 4-triazole as reaction raw materials, selects the magnetic nano sulfonic acid as the catalyst, and has higher activity and efficiency in preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative by catalysis of the catalyst, so that the utilization rate of the reaction raw materials and the yield of the obtained product can be effectively improved, and the catalyst has higher selectivity, can effectively reduce the occurrence of side reactions and is beneficial to ensuring the purity of the obtained product.

(2) According to the method for preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative through catalysis, the catalyst is good in cycle performance, can be recycled for multiple times without treatment, and is good in stability of catalytic activity in the process of recycling, so that the yield of the obtained product can be effectively guaranteed, and cost saving is facilitated.

(3) According to the method for preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative through catalysis, an ethanol-dimethylformamide aqueous solution is selected as a reaction solvent and a recrystallization solvent, and technological parameters such as the addition amount of the reaction solvent, the volume ratio of components in the reaction solvent, the reaction temperature, the reaction time and the like are optimally designed, so that on one hand, the occurrence of side reactions can be effectively prevented, the purity of the obtained product can be further ensured, on the other hand, the catalytic activity of the catalyst can be best exerted, and the yield of the obtained product can be ensured.

(4) The method for preparing the dihydro [1, 2, 4] triazolo [1, 5-a ] pyrimidine derivative through catalysis is simple in preparation process, particularly simple in product separation process, free of independently setting a purification process, short in whole reaction time, economical and efficient, the reaction solvent can be recycled along with the catalyst, and the waste liquid discharge amount is small.

Drawings

FIG. 1 is a schematic representation of the effect of the number of catalyst system cycles on the yield and purity of the product obtained in example 1;

FIG. 2 is a graph comparing the yields of the products obtained in example 1 and comparative examples 1 to 5;

FIG. 3 is a graph showing a comparison of the purity of the products obtained in example 1 and comparative examples 6 to 9;

FIG. 4 is a graphical representation of the effect of the number of catalyst system cycles on the yield and purity of the product obtained in example 2;

FIG. 5 is a graphical representation of the effect of the number of catalyst system cycles on the yield and purity of the product obtained in example 3.

Detailed Description

The essential features and the remarkable effects of the present invention can be obtained from the following examples, which are not intended to limit the present invention in any way, and those skilled in the art who have the benefit of this disclosure will be able to make numerous insubstantial modifications and adaptations to the present invention without departing from the scope of the present invention. The invention is further illustrated by the following specific embodiments, in which the test characterization of the reaction products in the examples uses a magnetic resonance spectrometer of AVANCE-II 400MHz, from Bruker, Germany; the infrared spectrum test and characterization adopts a Bruker tenor 37FT-IR infrared spectrometer of Germany Bruker company and KBr tabletting; the liquid chromatography purity measurement adopts a 2489 high performance liquid chromatograph of Waters corporation in the United states; the melting point of the reaction product was determined by the capillary method.