阅读说明：本技术 一种3-（1-氨基环丙基）苯甲酸甲酯的合成方法 (Synthetic method of 3- (1-aminocyclopropyl) methyl benzoate ) 是由 刘超 戴红升 于 2021-02-05 设计创作，主要内容包括：本发明属于医药中间体技术领域,具体涉及一种3-(1-氨基环丙基)苯甲酸甲酯的合成方法。本发明的合成方法为以3-氰基苯甲酸甲酯作为原料,利用钛酸四异丙酯与3-氰基苯甲酸甲酯进行反应,形成络合物,保护3-氰基苯甲酸甲酯中的酯基,再与乙基溴化镁进行加成反应,最后在三氟化硼提供酸环境的作用下关环,反应,得到3-(1-氨基环丙基)苯甲酸甲酯。(The invention belongs to the technical field of medical intermediates, and particularly relates to a synthetic method of 3- (1-aminocyclopropyl) methyl benzoate. The synthesis method comprises the steps of taking 3-cyanomethyl benzoate as a raw material, reacting tetraisopropyl titanate with 3-cyanomethyl benzoate to form a complex, protecting an ester group in the 3-cyanomethyl benzoate, performing addition reaction with ethyl magnesium bromide, and finally closing a ring under the action of boron trifluoride providing an acid environment to perform reaction to obtain the 3- (1-aminocyclopropyl) methyl benzoate.)

1. A synthetic method of 3- (1-aminocyclopropyl) methyl benzoate is disclosed, wherein the structure of the 3- (1-aminocyclopropyl) methyl benzoate is as follows:

，

the synthesis method is characterized in that 3-cyanomethyl benzoate is used as a raw material, tetraisopropyl titanate and 3-cyanomethyl benzoate are reacted to form a complex, ester groups in the 3-cyanomethyl benzoate are protected, then the complex is subjected to addition reaction with ethyl magnesium bromide, and finally ring closure is carried out under the action of boron trifluoride providing an acid environment to react to obtain the 3- (1-aminocyclopropyl) methyl benzoate.

2. The synthesis method of methyl 3- (1-aminocyclopropyl) benzoate according to claim 1, characterized in that the synthesis method comprises the steps of putting methyl 3-cyanobenzoate and toluene into a reactor, stirring, cooling to-30 to-20 ℃ under the protection of nitrogen, adding tetraisopropyl titanate, stirring, adding ethyl magnesium bromide solution, controlling the temperature to-30 to-20 ℃, stirring, finally adding 0.3mol/L boron trifluoride diethyl etherate solution, and carrying out heat preservation reaction to obtain the methyl 3- (1-aminocyclopropyl) benzoate.

3. The method for synthesizing methyl 3- (1-aminocyclopropyl) benzoate according to claim 2, wherein the mass ratio of methyl 3-cyanobenzoate to tetraisopropyl titanate is 2:3 to 5.

4. The method for synthesizing methyl 3- (1-aminocyclopropyl) benzoate according to claim 2, wherein the mass ratio of methyl 3-cyanobenzoate to ethyl magnesium bromide is 2: 2-6.

5. The synthesis method of methyl 3- (1-aminocyclopropyl) benzoate according to claim 2, characterized in that the solid-liquid g/mL ratio of methyl 3-cyanobenzoate to 0.3mol/L boron trifluoride ethyl ether solution is 2:3 to 5.

Technical Field

The invention belongs to the technical field of medical intermediates, and particularly relates to a synthetic method of 3- (1-aminocyclopropyl) methyl benzoate.

Background

The synthesis method of the compound 3- (1-aminocyclopropyl) methyl benzoate and related derivatives have wide application in pharmaceutical chemistry and organic synthesis. At present, the synthesis method of 3- (1-aminocyclopropyl) methyl benzoate is only reported in documents. Therefore, it is necessary to develop a synthesis method which has easily available raw materials, convenient operation, easy control of reaction, proper overall yield and suitability for industrial production.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: aiming at the problem, the synthesis method of the methyl 3- (1-aminocyclopropyl) benzoate is provided.

In order to solve the technical problems, the invention adopts the following technical scheme:

a synthetic method of 3- (1-aminocyclopropyl) methyl benzoate is disclosed, wherein the structure of the 3- (1-aminocyclopropyl) methyl benzoate is as follows:

，

the synthesis method comprises the steps of taking 3-cyanomethyl benzoate as a raw material, reacting tetraisopropyl titanate with 3-cyanomethyl benzoate to form a complex, protecting an ester group in the 3-cyanomethyl benzoate, performing addition reaction with ethyl magnesium bromide, and finally closing a ring under the action of boron trifluoride providing an acid environment to perform reaction to obtain the 3- (1-aminocyclopropyl) methyl benzoate.

Preferably, the synthesis method comprises the steps of putting 3-cyanobenzoic acid methyl ester and toluene into a reactor, stirring, protecting with nitrogen, cooling to-30-20 ℃, adding tetraisopropyl titanate, stirring, adding an ethyl magnesium bromide solution, controlling the temperature to-30-20 ℃, stirring, finally adding a 0.3mol/L boron trifluoride diethyl etherate solution, and carrying out heat preservation reaction to obtain the 3- (1-aminocyclopropyl) benzoic acid methyl ester.

Preferably, the mass ratio of the methyl 3-cyanobenzoate to the tetraisopropyl titanate is 2: 3-5.

Preferably, the mass ratio of the methyl 3-cyanobenzoate to the ethyl magnesium bromide is 2: 2-6.

Preferably, the solid-liquid g/mL ratio of the methyl 3-cyanobenzoate to the 0.3mol/L boron trifluoride ethyl ether solution is 2: 3-5.

Compared with other methods, the method has the beneficial technical effects that:

(1) the invention provides a synthetic method of 3- (1-aminocyclopropyl) methyl benzoate, and provides a synthetic route for the synthetic method of 3- (1-aminocyclopropyl) methyl benzoate;

(2) the synthetic method of the methyl 3- (1-aminocyclopropyl) benzoate is short in route, reasonable in design, simple to operate and easy to control;

(3) the product obtained by the method has high yield.

Detailed Description

A synthetic method of 3- (1-aminocyclopropyl) methyl benzoate comprises the following steps: according to the mass ratio of 2: 3-5 of methyl 3-cyanobenzoate to tetraisopropyl titanate, the solid-liquid g/mL ratio of methyl 3-cyanobenzoate to ethyl magnesium bromide is 2: 2-6, the solid-liquid g/mL ratio of methyl 3-cyanobenzoate to 0.3mol/L boron trifluoride diethyl etherate is 2: 3-5, taking materials, putting methyl 3-cyanobenzoate and toluene into a reactor, stirring, protecting with nitrogen, cooling to-30-20 ℃, adding tetraisopropyl titanate, stirring, adding ethyl magnesium bromide, controlling the temperature to-30-20 ℃, stirring, finally adding 0.3mol/L boron trifluoride diethyl etherate, and carrying out heat preservation reaction to obtain the methyl 3- (1-aminocyclopropyl) benzoate.

Example 1

A synthetic method of 3- (1-aminocyclopropyl) methyl benzoate comprises the following steps: placing 20g of 3-cyanobenzoic acid methyl ester and 300mL of toluene into a reactor, stirring, carrying out nitrogen protection, cooling to-20 ℃, adding 35g of tetraisopropyl titanate, stirring, adding 30g of ethylmagnesium bromide, controlling the temperature to-20 ℃, stirring, finally adding 40mL0.3mol/L boron trifluoride diethyl etherate solution, carrying out heat preservation reaction, detecting by TLC, reacting the raw materials, dropwise adding 3M hydrochloric acid (150 mL) into the reaction solution, carrying out liquid separation, retaining an organic phase, extracting an aqueous phase for 3 times (250 mL x 3) by using 2-methyltetrahydrofuran, combining the organic phases, washing with saturated sodium bicarbonate (200 mL), carrying out liquid separation, and concentrating the organic phase to dryness. Silica gel is stirred and is filtered to obtain 20.9g of yellow oily matter, namely the 3- (1-aminocyclopropyl) methyl benzoate with the yield of 95 percent and the purity of 99.2 percent.

1H NMR（d6-DMSO）: 7.96 (t, J = 1.7 Hz, 1H), 7.73 (dd, J = 8.2, 6.6 Hz, 1H), 7.52 (ddd, J = 7.8, 1.9, 1.3 Hz, 1H), 7.42 (d, J = 7.7 Hz, 1H), 3.85 (s, 3H), 0.98 (qd, J = 7.7, 5.3 Hz, 4H)。

Example 2

A synthetic method of 3- (1-aminocyclopropyl) methyl benzoate comprises the following steps: placing 20g of 3-cyanobenzoic acid methyl ester and 300mL of toluene into a reactor, stirring, carrying out nitrogen protection, cooling to-30 ℃, adding 35g of tetraisopropyl titanate, stirring, adding 30g of ethylmagnesium bromide, controlling the temperature to-30 ℃, stirring, finally adding 40mL0.3mol/L boron trifluoride diethyl etherate solution, carrying out heat preservation reaction, detecting by TLC, reacting the raw materials, dropwise adding 3M hydrochloric acid (150 mL) into the reaction solution, carrying out liquid separation, retaining an organic phase, extracting an aqueous phase for 3 times (250 mL x 3) by using 2-methyltetrahydrofuran, combining the organic phases, washing with saturated sodium bicarbonate (200 mL), carrying out liquid separation, and concentrating the organic phase to dryness. Silica gel was sampled and passed through a column to obtain 21.3g of yellow oil, i.e., methyl 3- (1-aminocyclopropyl) benzoate in 96.9% yield and 99.1% purity.

1H NMR（d6-DMSO）: 7.96 (t, J = 1.7 Hz, 1H), 7.73 (dd, J = 8.2, 6.6 Hz, 1H), 7.52 (ddd, J = 7.8, 1.9, 1.3 Hz, 1H), 7.42 (d, J = 7.7 Hz, 1H), 3.85 (s, 3H), 0.98 (qd, J = 7.7, 5.3 Hz, 4H)。