CN111018734A - Synthesis method of cinacalcet hydrochloride intermediate - Google Patents

Abstract

The invention provides a preparation method of a cinacalcet hydrochloride intermediate (R) -N- (1- (naphthalene-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propionamide. The method has the advantages of cheap and easily obtained raw materials, short reaction steps, high yield, simple post-treatment, easy operation, cost reduction, certain technical advantages and suitability for large-scale industrial production.

Description

Synthesis method of cinacalcet hydrochloride intermediate

Technical Field

The invention relates to the field of synthesis of pharmaceutical intermediates, in particular to a preparation method of a cinacalcet hydrochloride intermediate (R) -N- (1- (naphthalene-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propionamide. The information provided is intended only to aid the reader in understanding. Neither the information provided nor the references cited are admissions of prior art for the invention. Each reference cited is incorporated herein in its entirety and can be used for any purpose.

Background

Cinacalcet hydrochloride (Cinacalcet hydrochloride), chemical name is N- [ (1R) -1- (1-naphthyl) ethyl]-3- [3- (trifluoromethyl) phenyl]Propylamine hydrochloride isThe second generation calcimimetic developed by NPS Pharmaceuticals in the united states was first marketed in 2004 in the united states. Is clinically used for treating secondary hyperparathyroidism of Chronic Kidney Disease (CKD) patients undergoing dialysis and hypercalcemia of parathyroid tumor patients. The main pharmacological action of the product is to reduce Ca²⁺The fixed point is adjusted to improve the sensitivity of calcium sensitive receptor to extracellular calcium, reduce the level of parathyroid hormone and make the serum Ca²⁺The concentration is reduced, thereby producing a series of clinical treatment effects and having the characteristics of high safety, good tolerance, convenient taking and the like.

The synthesis method of cinacalcet hydrochloride has been reported in various documents, and the following seven synthesis routes are mainly adopted:

1) using 3-trifluoromethyl amphetamine and 1-acetonaphthone as initial raw materials, and adding Ti (OiPr)₄Condensing under catalysis, reducing by nitrile sodium borohydride, and finally separating by a chiral column to obtain a target compound [ Van, W.B.C., Moe, S.T., Balandrin, M.F., et al (2001) Calcimeter-active compounds: US, 6211244.2001-04-03]. The Ti (OiPr) used in the first step of the process₄The price is high, the post-treatment is very difficult, the anhydrous requirement is high, and the initial raw material 3-trifluoromethyl amphetamine is expensive and not easy to obtain; in the second step, sodium cyanoborohydride is adopted for reducing unsaturated double bonds, so that the price is high, and the post-treatment is troublesome; in addition, the target product needs to be separated by a chiral chromatographic column, can be prepared in a small amount, and is not suitable for industrial production.

2) Using 3-trifluoromethylphenylpropyl aldehyde and (R) -1-naphthylethylamine as starting materials in Ti (OiPr)₄Carrying out condensation reaction under catalysis, and then reducing and salifying by sodium cyanoborohydride to obtain cinacalcet hydrochloride [ Sorbera, L.A., Castaner, R.M.and Bayes, M. (2002) Cinacalce thydrochloride, which is a derivative of synergistic hydrolysis, drugs of Future,27, 831-836-]. The process route is simple, but the key raw material 3-trifluoromethyl phenylpropyl aldehyde in the route is difficult to prepare and purchase and has high price; while the route is also usedRelatively expensive Ti (OiPr)₄This is not favorable for cost reduction.

3) 1-bromo-3-trifluoromethylbenzene is used as a raw material, ethyl 3-trifluoromethylcinnamate is obtained through Heck reaction, meta-trifluoromethylphenylpropanol is obtained through reduction of palladium carbon and lithium aluminum hydride, a nucleophilic substitution reaction is carried out on the meta-trifluoromethylphenylpropanol and (R) -1-naphthylethylamine after a halide is prepared, and finally, cinacalcet hydrochloride [ Lifshitz-Liron, R.R., Eisensstadt, A.A., Wizel, S.et., ethyl. (2006) Process for preparing of cinacalcet hydrochloride: WO2006125026] is obtained through salification. Firstly, ethyl acrylate is used for synthesizing the 3-trifluoromethyl ethyl cinnamate in the process, the reagent is a known carcinogen, and the reagent should be avoided as much as possible in the industrial production process for safety; second, Heck coupling requires the use of more expensive palladium catalysts, which is not cost effective.

4) Chiral tert-butyl sulfamide, 1-naphthyl ethyl ketone and 3-trifluoromethyl benzaldehyde are used as initial raw materials to synthesize two side chains: (R) -1-naphthylethylamine protected by tert-butylsulfonyl group and m-trifluoromethylphenylpropyl halide, and then condensation, deprotection and salification are carried out to prepare cinacalcet hydrochloride [ Arava, V.R., Gorentla, L.and Dubey, P.K. (2012) A novalasymetric synthesis of cinacalchloride hydrochloride. Beilstein Journal of organic chemistry,1,1366-]. The process has long synthesis steps and high chiral raw material price, and needs to use a catalyst Ti (OEt)₄The strong base of hexamethyldisilazane lithium amide (LiHMDS) has higher cost; the reaction time of the first step is too long (30h), the reaction needs to be carried out at minus 48 ℃, the requirement on equipment is high, the separation difficulty of the intermediate is high, and the method is comprehensively considered and is not suitable for large-scale industrial production.

5) 3-bromotrifluorotoluene and N-allyl- (R) -1-naphthylethylamine are used as starting materials to obtain an unsaturated cinacalcet intermediate under the catalysis of Pd or Ni, and then the unsaturated cinacalcet intermediate is reduced by palladium carbon and salified to obtain cinacalcet [ Bernard, C., Larsen, R., Martinelli, M.J., et al (2012) Methods of synthesizing cinacalcet and saltshere, US8183415 ]. The process has short steps and is convenient for quality control, but the intermediate N-allyl- (R) -1-naphthylethylamine has high preparation difficulty and is difficult to purchase, a protecting group is required to protect nitrogen atoms under most conditions, reaction steps are increased, and the Heck coupling reaction needs to use a metal catalyst with high price, so that the process is not beneficial to industrialization.

6) (R) -1-naphthylethylamine and benzaldehyde are used as starting materials to react to prepare an imine intermediate, then the imine intermediate is condensed with 3-trifluoromethylphenylpropyl bromide in the presence of NMP to generate imine salt, and finally benzaldehyde is removed to form salt so as to obtain cinacalcet hydrochloride [ Shide, G.B., Niphade, N.C., Deshmukh, S.P., et al (2011) Industrial application for reaction: Novel one-point synthesis of cinacalcet hydrochloride, acetic clinical agent, organic Process Research & Development,15, 455 ]. In the route, an imine intermediate prepared by reacting the raw material (R) -1-naphthylethylamine with benzaldehyde is unstable, is difficult to store and has complex post-treatment; in addition, 3-trifluoromethyl phenylpropyl bromide is expensive, has a gene warning structure and needs extra attention for quality research.

7) 3-trifluoromethylphenylpropionic acid is used as a starting material to prepare acyl chloride, the acyl chloride is condensed with (R) -1-naphthylethylamine, and the obtained product is reduced by a reducing agent such as lithium aluminum hydride or borane to form salt so as to prepare cinacalcet hydrochloride [ a) Lifshitz-Liron, R. (2007) a Process for the preparation of the chloride base: WO2007127445.b) Thiel, O.R., Bernard, C., Tormos, W., et al (2008) a pharmaceutical synthesis of the calcium chloride precursors Letters,49,13-15.c) Bijukumar, G., Maloyeyer, B, Bhaska, B.S., 2008, et al (2008) an effective synthesis of chloride synthesis, 15138. Committer.7 ]. The process has the advantages of short steps, mild conditions and development value, but the price of the raw material 3-trifluoromethylphenyl propanoic acid is high, the synthesis of the process generally takes 3-trifluoromethylbenzaldehyde as the raw material, the 3-trifluoromethylphenyl propanoic acid is condensed with malonic acid derivatives through Knoevenagel, and then Pd/C catalytic hydrogenation is carried out, so the production cost is high; in addition, the intermediate acyl chloride is unstable and is not easy to store, and the like, and further improvement and optimization are needed.

In view of the deficiencies of the above process routes, the present invention provides a synthetic route and a preparation method of cinacalcet hydrochloride intermediate (R) -N- (1- (naphthalen-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propionamide. The method comprises the steps of taking 3-trifluoromethyl benzaldehyde as a starting material, reacting with Meldrum's acid to obtain 2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione, reacting with (R) -1-naphthylethylamine, and decarboxylating to obtain a key intermediate of cinacalcet hydrochloride. The method has the advantages of short route, easily obtained raw materials, low cost, simple and convenient operation, convenient separation and purification in each step, higher yield and good product quality, and can be used for large-scale industrial preparation of cinacalcet hydrochloride raw materials.

Disclosure of Invention

The application provides a preparation method of a cinacalcet hydrochloride intermediate (R) -N- (1- (naphthalene-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propionamide (formula IV), and the compound can be applied to preparation of cinacalcet hydrochloride (cinacalcet hydrochloride) bulk drug.

The invention provides a method for preparing cinacalcet intermediate IV, which comprises the following steps:

step (1): preparing a compound of formula II from a compound of formula I:

under the condition of solvent or no solvent, the compound of formula I and Meldrum's acid are reacted under the action of proline/2, 6-dimethyl-1, 4-dihydro-3, 5-diethyl pyridinedicarboxylate or triethylamine/formic acid to prepare the compound of formula II. In some embodiments, the solvent is selected from one or more of water, methanol, ethanol, isopropanol, dichloromethane, acetonitrile, acetic acid, or pyridine. In other embodiments, the proline is selected from any one or a combination of DL-proline, L-proline or D-proline.

Step (2): preparing a compound of formula IV from a compound of formula II:

reacting a compound of formula II with (R) -1- (1-naphthyl) ethylamine or a salt thereof in the presence or absence of a solvent to produce a compound of formula IV.

In some particular embodiments, compounds of formula IV are prepared with (R) -1- (1-naphthyl) ethylamine or a salt thereof in the presence of an acid or base selected from acetic acid, p-toluenesulfonic acid, triethylamine, diisopropylethylamine, pyridine, N-methylpiperidine, N-methylmorpholine, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, sodium bicarbonate, sodium methoxide, potassium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, sodium acetate, potassium acetate, N-butyllithium or diisopropyllithium and the like, with or without a solvent.

In some preferred embodiments, the solvent in step (2) is selected from one or more of water, methanol, ethanol, propanol, isopropanol, tert-butanol, N-butanol, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, acetonitrile, toluene, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone.

In some further preferred embodiments, wherein the solvent in step (2) is selected from one or more of water, methanol, ethanol, propanol, isopropanol, tert-butanol, N-butanol, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, acetonitrile, toluene, dimethylsulfoxide, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone; the equivalent weight of the (R) -1- (1-naphthyl) ethylamine or the salt thereof is 0.5-5.0 equivalent weight.

In some preferred embodiments, the compound of formula IV is prepared with (R) -1- (1-naphthyl) ethylamine at-20 to 200 ℃ in the presence or absence of a solvent selected from one or more of water, methanol, ethanol, propanol, isopropanol, tert-butanol, N-butanol, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, acetonitrile, toluene, dimethylsulfoxide, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone; the equivalent weight of the (R) -1- (1-naphthyl) ethylamine is 0.5-5.0 equivalent weight.

In some particularly preferred embodiments, the compound of formula IV is prepared with (R) -1- (1-naphthyl) ethylamine at 0 to 150 ℃ with or without a solvent selected from one or more of water, methanol, ethanol, propanol, isopropanol, tert-butanol, N-butanol, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, acetonitrile, toluene, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone; the equivalent weight of the (R) -1- (1-naphthyl) ethylamine is 0.5-5.0 equivalent weight.

In some embodiments, the process for preparing formula IV from a compound of formula I comprises the steps of:

wherein, in the process of step (1), the compound of formula I and Meldrum's acid are reacted under the action of potassium phosphate, piperidine, pyridine or piperidine acetate to prepare the compound of formula I-1, wherein the compound of formula I-1 can be used in the process of step (2) without isolation;

in the process of the step (2), in a solvent, I-1 is used for preparing a compound shown in a formula II under the action of a reducing agent, wherein the reducing agent is any one or combination of sodium borohydride, potassium borohydride, sodium cyanoborohydride and sodium triacetyl borohydride;

wherein, the solvent in the step (1) and the step (2) is selected from one or more of water, methanol, ethanol, isopropanol, dichloromethane, acetonitrile, acetic acid or pyridine.

In some embodiments, the process for preparing formula IV from a compound of formula I comprises the steps of:

wherein, in the process of the step (1), under the condition of solvent or no solvent, the compound shown in the formula II reacts with (R) -1- (1-naphthyl) ethylamine or a salt thereof at the temperature of-20-100 ℃ to prepare the compound shown in the formula III-1, wherein the compound shown in the formula III-1 can be directly used in the process of the step (2) without separation;

in the process of the step (2), the compound shown in the formula III-1 is decarboxylated at 50-200 ℃ to prepare the compound shown in the formula IV under the condition of solvent or no solvent.

In other embodiments, the process for preparing formula IV from the compound of formula I comprises the steps of:

wherein, in the process of the step (1), the compound of the formula II is used for preparing the compound of the formula III-2 under the action of acid or alkali in a solvent;

wherein, in the step (2), the compound of formula III-2 and (R) -1- (1-naphthyl) ethylamine or a salt thereof are condensed to prepare the compound of formula IV under the condition of solvent or no solvent.

By means of the scheme, compared with the prior art, the invention has the following advantages: the invention provides a preparation method of (R) -N- (1- (naphthalene-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propionamide (formula IV), which can be used for synthesizing Cinacalcet hydrochloride (Cinacalcite hydrochloride) bulk drug. The method has the advantages of short synthetic route, cheap and easily-obtained raw materials, avoidance of heavy metal catalyzed hydrogenation reaction, simple overall process, strong operability and suitability for industrial production.

Detailed Description

The preparation process described in the present invention is further illustrated by the following examples, which include, but are not limited to.

The following examples are intended only to illustrate specific embodiments of the present invention, so as to enable those skilled in the art to more fully understand the present invention, but not to limit the present invention in any way. In the embodiments of the present invention, technical means or methods which are not specifically described are conventional in the art.

The chemicals used in the following examples are all commercially available chemicals.

In an exemplary embodiment of the invention, the synthetic route for formula IV is as follows:

in the above synthetic routes, those skilled in the art can also make changes to the above synthetic routes, such as changing specific reaction conditions or making adjustments to the synthetic route of one or more steps, etc., as needed, and such changes are within the scope of the present application without departing from the spirit of the present invention.

EXAMPLE 12 Synthesis of 2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione

L-proline (4.07g,35.0mmol) was added to a mixture of 3-trifluoromethylbenzaldehyde (30.3g,174mmol) and Meldrum's acid (25.6g,174mmol) in ethanol (996mL) at room temperature. After 40 minutes, diethyl 1, 4-dihydro-2, 6-dimethyl-3, 5-pyridinedicarboxylate (44.1g,174mmol) was added in one portion followed by ethanol (125 mL). After stirring overnight, the mixture was concentrated under reduced pressure to give a yellow solid. Isopropanol (300mL) was added and slurried at room temperature for 3 h. The mixture was filtered and the filter cake was washed with isopropanol. The solid was collected and dried in vacuo to give 47.9g of a white solid in 91% yield.

Example Synthesis of 22, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione

D, L-proline (4.07g,35.0mmol) was added to a mixture of 3-trifluoromethylbenzaldehyde (30.3g,174mmol) and Meldrum's acid (25.6g,174mmol) in acetonitrile (300mL) at room temperature. After 40 minutes, diethyl 1, 4-dihydro-2, 6-dimethyl-3, 5-pyridinedicarboxylate (44.1g,174mmol) was added in one portion. After stirring overnight, the mixture was concentrated under reduced pressure to give a yellow solid. Ethyl acetate (300mL) was added and extracted twice with 150mL of 5% aqueous sodium hydroxide, the collected alkali solution was cooled in an ice bath, the pH was carefully adjusted to about 4 with 6N hydrochloric acid to precipitate a white solid, which was allowed to stand for 5 minutes, collected and vacuum-dried to obtain 50.0g of a white solid with a yield of 95%.

Example Synthesis of 32, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione

To a solution of the micellic acid (4.3g,30.0mmol) in ethanol (100mL) was added potassium phosphate (1.3g,6.0mmol) followed by 3-trifluoromethylbenzaldehyde (5.2g,30.0mmol) with stirring. After 6h reaction at room temperature, the mixture was cooled in an ice bath, sodium borohydride (2.4g,62.0mmol) was added in portions, and the mixture was warmed to room temperature and reacted for 2 h. The reaction solution was concentrated to about 20mL, 100mL of 1N hydrochloric acid was added, extraction was performed with ethyl acetate, drying was performed with anhydrous sodium sulfate, filtration was performed, concentration was performed to dryness under reduced pressure, then, beating was performed with isopropanol (30mL), the mixture was filtered, and the filter cake was washed with isopropanol. The solid was collected and dried in vacuo to give 6.8g of a white solid in 75% yield.

Example Synthesis of 42, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione

To a reaction flask containing 3-trifluoromethylbenzaldehyde (5.2g,30.0mmol) and water (65mL) was added Meldrum's acid (4.5g,31.0mmol) in portions at room temperature, followed by warming to 75 ℃ for 2 h. Cool to room temperature, collect the solid by suction filtration, wash with ice water (100mL × 2) and petroleum ether (100mL), and dry in vacuo. The crude product (8.9g, 29.5mmol) was dissolved in dichloromethane (150mL), cooled to 0 deg.C, acetic acid (20mL) was added, stirred under nitrogen for 5min, and then sodium borohydride (4.5g,118.0mmol) was added carefully in portions. After the reaction solution became colorless, 100mL of water was added and the organic phase was separated and the aqueous phase was extracted once more with dichloromethane (50 mL). The organic phases were combined, washed with saturated brine (100mL x 2) and water (100mL x 2), dried over anhydrous sodium sulfate and concentrated to give 8.6g of product in 95% yield.

Example Synthesis of 52, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione

Meldrum's acid (4.5g,31.0mmol) and 3-trifluoromethylbenzaldehyde (5.2g,30.0mmol) were dissolved in anhydrous ethanol (50mL) and a catalytic amount of piperidine acetate (436mg,3.0mmol) was added. After stirring vigorously for 30min, the temperature was reduced to 0 ℃ and sodium cyanoborohydride (2.8g,45.0mmol) was added in portions over one hour, then allowed to warm to room temperature for reaction overnight. The reaction was quenched by careful addition of 10% HCl until no gas evolved and concentrated under reduced pressure. The residue was extracted with water (100mL), dichloromethane, dried over anhydrous sodium sulfate, filtered, concentrated, and the product was slurried with isopropanol to give 6.3g of a white solid in 69% yield.

Example 6 Synthesis of (R) -N- (1- (naphthalen-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propanamide

2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione (30.2g,100.0mmol) and (R) -1-naphthylethylamine (17.1g,100.0mmol) were added successively to a reaction flask and reacted at 100 ℃ for 5 h. After cooling to room temperature, the product is directly used for the next reaction of synthesizing cinacalcet, and the HPLC purity is more than 95 percent.

Example 7 Synthesis of (R) -N- (1- (naphthalen-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propanamide

2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione (30.2g,100.0mmol), (R) -1-naphthylethylamine (17.1g,100.0mmol) and DMF (100mL) were added successively to a reaction flask and reacted at 100 ℃ for 3 h. After cooling to room temperature, 300mL of 13% saline solution was added, stirring was continued for 30min, suction filtration was performed, the solid was collected, washed with water, and air-dried to obtain 35.5g of a white solid with a yield of 95%.

Example 8 Synthesis of (R) -N- (1- (naphthalen-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propanamide

2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione (30.2g,100.0mmol), (R) -1-naphthylethylamine (17.1g,100.0mmol) and toluene (200mL) were added to the reaction flask in this order and refluxed for 12 h. After cooling to room temperature, the mixture was washed once with 100mL of saturated sodium bicarbonate, 100mL of 1N hydrochloric acid and 100mL of water, dried over anhydrous sodium sulfate, and concentrated to obtain 35.7g of a white solid with a yield of 96%.

Example 9 Synthesis of (R) -N- (1- (naphthalen-1-yl) ethyl) -3- (3- (trifluoromethyl) phenyl) propanamide

2, 2-dimethyl-5- (3- (trifluoromethyl) benzyl) -1, 3-dioxo-4, 6-dione (3.0g,10.0mmol), (R) -1-naphthylethylamine hydrochloride (2.1g,10.0mmol), pyridine (5mL) and DMF (20mL) were added successively to a reaction flask and reacted at 100 ℃ for 3 h. After cooling to room temperature, 30mL of 13% saline solution was added, stirring was continued for 30min, suction filtration was performed, the solid was collected, washed with water, and air-dried to obtain 3.4g of a white solid with a yield of 91%.

The above-mentioned embodiments are merely exemplary embodiments for fully illustrating the present invention, and the scope of the present invention is not limited to the above-mentioned embodiments, but defined by the contents of the claims. All matters disclosed in the specification including the abstract and all methods and steps disclosed herein may be combined in any combination, except combinations where the features and/or steps are mutually exclusive. Each feature disclosed in this specification, including the abstract, can be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. Those skilled in the art should also make equivalents and modifications to the present invention without departing from the spirit and scope of the present invention. Such modifications are also within the scope of the present invention. Each reference cited in this application is incorporated herein in its entirety.

Claims (10)

1. A process for preparing a cinacalcet hydrochloride intermediate characterized by: the method comprises the following steps:

wherein in the process of the step (1), under the condition of solvent or no solvent, the compound of the formula I and the Meldrum's acid are used for preparing the compound of the formula II under the action of proline/diethyl 2, 6-dimethyl-1, 4-dihydro-3, 5-pyridinedicarboxylate or triethylamine/formic acid;

wherein, in the step (2), the compound of formula II is reacted with (R) -1- (1-naphthyl) ethylamine or a salt thereof in the presence of a solvent or in the absence of a solvent to prepare the compound of formula IV.

2. The process of claim 1, wherein the solvent in step (1) is selected from one or more of water, methanol, ethanol, isopropanol, dichloromethane, acetonitrile, acetic acid, or pyridine.

3. The method of claim 1, wherein the proline is selected from any one or combination of DL-proline, L-proline or D-proline.

4. The process of claim 1, wherein the compound of formula II and (R) -1- (1-naphthyl) ethylamine or a salt thereof in step (2) are reacted with an acid or a base selected from acetic acid, p-toluenesulfonic acid, triethylamine, diisopropylethylamine, pyridine, N-methylpiperidine, N-methylmorpholine, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, sodium bicarbonate, sodium methoxide, potassium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, sodium acetate, potassium acetate, N-butyllithium or diisopropyllithium to produce the compound of formula IV.

5. The process of claim 1, wherein the solvent in step (2) is selected from one or more of water, methanol, ethanol, propanol, isopropanol, tert-butanol, N-butanol, dichloromethane, tetrahydrofuran, methyltetrahydrofuran, methyl tert-butyl ether, acetonitrile, toluene, dimethyl sulfoxide, N-dimethylformamide, N-dimethylacetamide, or N-methylpyrrolidone.

6. The method according to claim 5, wherein the equivalent amount of the (R) -1- (1-naphthyl) ethylamine or the salt thereof in the step (2) is 0.5 to 5.0 equivalents.

7. The process according to claim 6, wherein the reaction temperature in step (2) is-20 to 200 ℃, preferably 0 to 150 ℃.

8. The method of claim 1, wherein the method comprises the steps of:

wherein, in the process of step (1), the compound of formula I and Meldrum's acid are reacted under the action of potassium phosphate, piperidine, pyridine or piperidine acetate to prepare the compound of formula I-1, wherein the compound of formula I-1 can be used in the process of step (2) without isolation;

in the process of the step (2), in a solvent, I-1 is used for preparing a compound shown in a formula II under the action of a reducing agent, wherein the reducing agent is any one or combination of sodium borohydride, potassium borohydride, sodium cyanoborohydride and sodium triacetyl borohydride;

wherein, the solvent in the step (1) and the step (2) is selected from one or more of water, methanol, ethanol, isopropanol, dichloromethane, acetonitrile, acetic acid or pyridine.

9. The method of claim 1, wherein the method comprises the steps of:

wherein, in the process of the step (1), under the condition of solvent or no solvent, the compound shown in the formula II reacts with (R) -1- (1-naphthyl) ethylamine or a salt thereof at the temperature of-20-100 ℃ to prepare the compound shown in the formula III-1, wherein the compound shown in the formula III-1 can be directly used in the process of the step (2) without separation;

in the process of the step (2), the compound shown in the formula III-1 is decarboxylated at 50-200 ℃ to prepare the compound shown in the formula IV under the condition of solvent or no solvent.

10. The method of claim 1, wherein the method comprises the steps of:

wherein, in the process of the step (1), the compound of the formula II is used for preparing the compound of the formula III-2 under the action of acid or alkali in a solvent;

wherein, in the step (2), the compound of formula III-2 and (R) -1- (1-naphthyl) ethylamine or a salt thereof are condensed to prepare the compound of formula IV under the condition of solvent or no solvent.