A preparation method and use of lopinavir impurity T

Abstract

The invention discloses a preparation method of lopinavir impurity T, which comprises the following steps: firstly protecting compound 1 on a hydroxyl group to generate compound 2, then deprotecting compound 2 on an amino group to generate compound 3, then condensing compound 3 on CDI to generate compound 4, and finally deprotecting compound 4 on a hydroxyl group to obtain lopinavir impurity T. The invention also discloses a use of the lopinavir impurity T in detecting and / or controlling the quality of lopinavir. The invention provides a new idea for the synthesis of lopinavir impurity T. The synthetic route has simple and mild reaction conditions, and has high yield and purity, which can meet the preparation requirements of the impurity, and is of great significance to the research on lopinavir.

Description

Technical Field

[0001] The present invention relates to the technical field of drug synthesis, and in particular to a preparation method and application of a lopinavir impurity T. Background Art

[0002] Lopinavir was developed by Abbott Corporation in the United States and was approved by the U.S. FDA in March 1996. It was first launched in the United States, and then in September 2000, the lopinavir / ritonavir combination was launched. It was approved for marketing in China in 2007 under the trade name Kaletra, and is mainly used in clinical treatment of AIDS. Its chemical name is (2S,3S,5S)-2-(2,6-dimethylphenoxyacetyl)amino-3-hydroxy-5-[2S-(1-tetrahydropyrimidin-2-one)-3-methylbutyryl]amino-1,6-diphenyl-n-hexane, and its structural formula is:

[0003]

[0004] Lopinavir is a protease inhibitor for human immunodeficiency virus (HIV)-1 and HIV-2. Its mechanism of action is to block the cleavage of gag-pol polyprotein, resulting in the production of immature, inactive viral particles. Lopinavir, ritonavir and other antiretroviral drugs are used in combination to treat HIV-1 infection. Patent WO9721685 discloses its preparation method, and the synthetic route is as follows:

[0005]

[0006] N,N'-(2S,2'S,3S,3'S,5S,5'S)-5,5'-carbonyldi(aminediyl)bis(3-hydroxy-1,6-diphenylhexane-5,2-diyl)bis[2-(2,6-dimethylphenoxy)acetamide] (hereinafter referred to as lopinavir impurity T) is an impurity in the production process of lopinavir, which is of great significance to the quality control and impurity research of lopinavir. However, the prior art does not disclose the preparation method of lopinavir impurity T, so the art urgently needs to provide a new preparation method of lopinavir impurity T that has not been reported in similar articles. Summary of the invention

[0007] The object of the present invention is to provide a preparation method and use of lopinavir impurity T to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for preparing lopinavir impurity T, specifically, firstly protecting compound 1 via hydroxyl to generate compound 2, then deprotecting compound 2 via amino to generate compound 3, then condensing compound 3 via CDI to generate compound 4, and finally deprotecting compound 4 via hydroxyl to obtain lopinavir impurity T, the synthesis route is as follows:

[0010]

[0011] Wherein X is chlorine or bromine element.

[0012] As a further solution of the present invention: specifically comprising the following steps:

[0013] S1: Protection: Compound 1 reacts with benzyl halide at room temperature under the conditions of strong base and N,N-dimethylformamide solvent, and after the reaction, compound 2 is obtained by extraction, evaporation and recrystallization;

[0014] S2: Deprotection: In dichloromethane as solvent and under acidic conditions, the amino group of compound 2 obtained in step S1 is deprotected, and after the reaction is completed, compound 3 is obtained after distillation, washing and spin drying;

[0015] S3: condensation: under alkaline conditions and N,N-dimethylformamide as solvent, the compound 3 obtained in step S2 is reacted with a condensation reagent N,N'-carbonyldiimidazole, and after the reaction is completed, the compound 4 is obtained by washing with water, distillation, and column chromatography separation;

[0016] S4: Deprotection: Compound 4 obtained in step S3 is deprotected by ammonium formate in the presence of ethanol as solvent and 10% palladium on carbon as catalyst. After the reaction is completed, lopinavir impurity T is obtained by filtration, distillation and column chromatography.

[0017] As a further scheme of the present invention: the strong base described in step S1 is any one of sodium hydroxide, potassium hydroxide, and sodium hydride; the benzyl halide is any one of benzyl chloride and benzyl bromide; the recrystallization solvent is any one of methanol, ethanol, isopropanol, ethyl acetate, or any one of a mixed solvent of methanol and water, ethanol and water, isopropanol and water, ethyl acetate and n-hexane, and ethyl acetate and n-heptane.

[0018] As a further solution of the present invention: the acid described in step S2 is any one of hydrochloric acid, sulfuric acid, and trifluoroacetic acid.

[0019] As a further scheme of the present invention: the base used in the alkaline conditions described in step S3 is any one of diisopropylethylamine, triethylamine, pyridine, 4-dimethylaminopyridine, sodium carbonate, and potassium carbonate; the molar ratio of the compound 3 to the condensation reagent N,N'-carbonyldiimidazole is (2-2.5):1; the purification method of the compound 4 is column chromatography, and the eluent is n-hexane:ethyl acetate = (5:1)-(1:1).

[0020] As a further solution of the present invention: the molar ratio of compound 4 to ammonium formate in step S4 is 1:

[0021] (3-6), the mass ratio of compound 4 to 10% palladium on carbon is 1:(0.1-0.8); the purification method of the lopinavir impurity T is column chromatography, and the eluent is n-hexane:ethyl acetate = (5:1)-(1:1).

[0022] As a further solution of the present invention: the present invention also discloses the use of the lopinavir impurity T prepared by the method of the present invention in detecting and / or controlling the quality of lopinavir.

[0023] Compared with the prior art, the invention has the following beneficial effects: the invention uses a new synthesis route to complete the preparation of lopinavir impurity T; the starting materials of the synthesis method are easily available, the reaction conditions are simple and mild, the yield is high, the reaction operation is simple, and the reaction is safe and environmentally friendly; through the synthesis of lopinavir impurity T, the dilemma of being difficult to purchase in the market is solved, the prepared lopinavir impurity T has high purity and meets the requirements for lopinavir impurity analysis, which is of great significance to the quality research of lopinavir. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The synthetic route of the lopinavir impurity T described in the embodiment of the present invention;

[0025] Figure 2 This is the H NMR spectrum of the lopinavir impurity T prepared in an embodiment of the present invention;

[0026] Figure 3 This is the NMR carbon spectrum of the lopinavir impurity T prepared in the embodiment of the present invention;

[0027] Figure 4 This is the LC-MS spectrum of the lopinavir impurity T prepared in the embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 The present invention discloses a method for preparing a lopinavir impurity T, which comprises first protecting a compound 1 via a hydroxyl group to generate a compound 2, then deprotecting the compound 2 via an amino group to generate a compound 3, then condensing the compound 3 via CDI to generate a compound 4, and finally deprotecting the compound 4 via a hydroxyl group to obtain the lopinavir impurity T. The specific embodiments are as follows:

[0030] Example 1

[0031] S1: Protection: Add NaH (1.5 g, 36.6 mmol) and DMF 100 ml to a 250 ml reaction bottle, stir at 0-10 ° C for 10 min, add compound 1 (20 g, 36.6 mmol), stir at 0-30 ° C for 30 min, slowly add BnBr (7.5 g, 43.9 mmol), add dropwise, stir at room temperature for 4 h, and monitor the reaction by TLC (n-hexane: ethyl acetate = 1: 1). After the reaction is completed, pour the reaction solution into 200 ml of water, add 100 ml of ethyl acetate, stir and stand for separation. Wash the ethyl acetate layer with 100 ml of water × 2, evaporate to dryness under reduced pressure at ≤45 ° C, and obtain 23 g of oil. Add 30 ml of isopropanol to the obtained solid, heat and reflux to dissolve, cool to 0-10 ° C, keep warm and stir for 1 h, filter with suction, and evaporate the filter cake under reduced pressure at ≤45 ° C to obtain 8.3 g of white solid of compound 2, and the yield of compound 2 is 78.5%.

[0032] S2: Deprotection of amino group: Compound 2 (15 g, 23.6 mmol) and 120 ml of dichloromethane were added to a 250 ml reaction bottle, stirred at room temperature to dissolve, and a solution of trifluoroacetic acid (29.6 g, 259.1 mmol) and 15 ml of dichloromethane was added dropwise at 25-30°C, and the mixture was kept at 25-30°C for 2 h. The reaction was monitored by TLC (n-hexane: ethyl acetate = 3: 1). After the reaction was completed, the mixture was evaporated to dryness under reduced pressure at ≤45°C, 100 ml of ethyl acetate was added to the residue, stirred to dissolve, and washed with 10% NaHCO3 150 g and water 150 g in sequence. The ethyl acetate phase was evaporated to dryness under reduced pressure at ≤45°C to obtain 12.1 g of an oily compound 3, and the yield of the obtained compound 3 was 96.0%.

[0033] S3: Condensation: Compound 3 (10.0 g, 18.6 mmol) and DMF 20 ml were added to a 100 ml reaction bottle, stirred to dissolve, CDI (1.3 g, 8.3 mmol) and DIPEA (2.4 g, 18.6 mmol) were added, and the reaction was stirred overnight at room temperature under nitrogen protection. After the reaction was completed, ethyl acetate 100 ml and water 100 ml were added to the reaction bottle, stirred and allowed to stand for separation, the organic phase was washed with water 100 ml and saturated brine 100 ml, the organic phase was evaporated to dryness under reduced pressure at ≤45°C, and the residue was subjected to column chromatography (n-hexane: ethyl acetate = 1:1) to obtain 13.2 g of foamy solid of compound 4, and the yield of compound 4 was 64.4%.

[0034] S4: Hydroxyl deprotection: Compound 4 (5 g, 4.5 mmol), 50 ml of ethanol, 2.5 g of water were added to a 250 ml reaction bottle, stirred to dissolve, and ammonium formate (1.3 g, 20.5 mmol) and 0.5 g of 10% Pd / C were added. Under nitrogen protection, the temperature was raised to reflux for reaction, and the reaction was monitored by TLC (n-hexane: ethyl acetate = 3: 1). The raw material reacted completely, cooled to room temperature, filtered through diatomaceous earth, the filter cake was rinsed with a small amount of ethanol, the filtrate was evaporated to dryness under reduced pressure, 50 ml of dichloromethane was added to the residue to dissolve, and washed with 50 g of saturated 10% NaHCO3 and 50 g of saturated brine in turn, the dichloromethane phase was evaporated to dryness under reduced pressure at ≤45°C, and column chromatography (n-hexane: ethyl acetate = 1: 1) was performed to obtain 3.7 g of lopinavir impurity T, with a yield of 88.6% and a purity of 97.4%.

[0035] The impurity T of Lopinavir obtained during the synthesis process was tested, and the test results are shown in Figure 2-4 , the relevant data are:

[0036] See also Figure 2 , its NMR hydrogen spectrum related data: 1 H NMR (600MHz, DMSO-d6) δ: 7.47 (d, J = 9.5Hz, 2H), 7.25 (d, J = 4.4Hz, 8H), 7.22-7.1 1 (m, 8H), 7.06 (d, J = 6.9Hz, 4H), 7.01 (d, J = 7.5Hz, 4H), 6.93 (m, 2H), 5.62 (d, J = 8. 6Hz, 2H), 5.04 (d, J=5.6Hz, 2H), 4.22 (m, 2H), 4.08-3.98 (m, 6H), 3.70 (d, J=6.6Hz , 2H), 2.81 (d, J=7.5Hz, 4H), 2.68-2.61 (m, 4H), 2.13 (s, 12H), 1.40-1.37 (q, 4H);

[0037] See also Figure 3 , NMR carbon spectrum related data:13 C NMR(600MHz,DMSO-d6)δ166.8,156.6,154.1,138.7,138.2,129.8,128.9,128.7,128.4,127 .6,127.5,125.5,125.3,123.8,69.8,67.7,52.5,46.6,39.9,39.5,38.7,38.5,37.2,15.5;

[0038] See also Figure 4 , its LC-MS related data: LC-MS (m / z): 919.5 [M+H] + ,941.5[M+Na] + .

[0039] Example 2

[0040] The difference from Example 1 is that in step S3, the molar ratio of the compound 3 to the condensation reagent N,N'-carbonyldiimidazole (CDI) is 2:1, and the yield of the obtained compound 4 is 63.5%.

[0041] Example 3

[0042] The difference from Example 1 is that the molar ratio of the compound 3 to the condensation reagent N,N'-carbonyldiimidazole (CDI) in step S3 is 2.5:1, and the yield of the obtained compound 4 is 63.1%.

[0043] Example 4

[0044] The difference from Example 1 is that the purification method of compound 4 in step S3 is column chromatography, the eluent is n-hexane:ethyl acetate=5:1, and the yield of compound 4 is 62.8%.

[0045] Example 5

[0046] The difference from Example 1 is that the purification method of compound 4 in step S3 is column chromatography, the eluent is n-hexane:ethyl acetate=3:1, and the yield of compound 4 is 63.6%.

[0047] Example 6

[0048] The difference from Example 1 is that the molar ratio of compound 4 to ammonium formate in step S4 is 1:3, and the yield of lopinavir impurity T is 87.1% and the purity is 97.2%.

[0049] Example 7

[0050] The difference from Example 1 is that the molar ratio of compound 4 to ammonium formate in step S4 is 1:6, and the yield of lopinavir impurity T is 85.5% and the purity is 96.8%.

[0051] Example 8

[0052] The difference from Example 1 is that in step S4, the mass ratio of compound 4 to 10% palladium on carbon is 1:0.5, and the yield of lopinavir impurity T is 86.7% and the purity is 97.1%.

[0053] Example 9

[0054] The difference from Example 1 is that in step S4, the mass ratio of compound 4 to 10% palladium on carbon is 1:0.8, and the yield of lopinavir impurity T is 85.3% and the purity is 96.5%.

[0055] Example 10

[0056] The difference from Example 1 is that the purification method of the lopinavir impurity T in step S4 is column chromatography, and the eluent is n-hexane: ethyl acetate = 5:1, and the yield of lopinavir impurity T is 86.9% and the purity is 97%.

[0057] Embodiment 11

[0058] The difference from Example 1 is that the purification method of the lopinavir impurity T in step S4 is column chromatography, and the eluent is n-hexane: ethyl acetate = 2.5:1, and the yield of lopinavir impurity T is 84.9% and the purity is 96.6%.

[0059] It can be seen from the above description that the above embodiments of the present invention achieve the following technical effects:

[0060] Comparing Examples 1, 2, and 3, it can be seen that in the condensation reaction, limiting the molar ratio of the compound 3 to the condensation reagent N,N'-carbonyldiimidazole (CDI) to within the preferred range of the present application is beneficial to improving the yield of the condensation reaction product.

[0061] Comparison of Examples 1, 4 and 5 shows that, in the condensation reaction, limiting the amount of the eluent n-hexane:ethyl acetate used for purification of compound 4 to within the preferred range of the present application is beneficial to improving the yield of the condensation reaction product.

[0062] Comparison of Examples 1, 6, and 7 shows that, in the hydroxyl deprotection reaction, limiting the molar ratio of compound 4 to ammonium formate to within the preferred range of the present application is beneficial to improving the yield and purity of lopinavir impurity T.

[0063] Comparison of Examples 1, 8, and 9 shows that, in the hydroxyl deprotection reaction, limiting the feed mass ratio of compound 4 to 10% palladium on carbon to within the preferred range of the present application is beneficial to improving the yield and purity of lopinavir impurity T.

[0064] Comparison of Examples 1, 10, and 11 shows that in the hydroxyl deprotection reaction, limiting the amount of the eluent n-hexane:ethyl acetate used for the purification of the lopinavir impurity T to within the preferred range of the present application is beneficial to improving the yield and purity of the lopinavir impurity T.

[0065] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0066] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0067] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing lopinavir impurity T, characterized in that: Specifically, compound 1 is first protected at the hydroxyl group to generate compound 2, and compound 2 is then deprotected at the amino group to generate compound 3, and then compound 3 is condensed at CDI to generate compound 4, and finally compound 4 is deprotected at the hydroxyl group to obtain lopinavir impurity T. The synthetic route is as follows: Wherein X is chlorine or bromine element.

2. The method for preparing a lopinavir impurity T according to claim 1, characterized in that: The specific steps include: S1: Protection: Compound 1 reacts with benzyl halide at room temperature under the conditions of strong base and N,N-dimethylformamide solvent, and after the reaction is completed, compound 2 is obtained by extraction, evaporation and recrystallization; S2: Deprotection: In dichloromethane as solvent and under acidic conditions, the amino group of compound 2 obtained in step S1 is deprotected, and after the reaction is completed, compound 3 is obtained after distillation, washing and spin drying; S3: condensation: under alkaline conditions and N,N-dimethylformamide as solvent, the compound 3 obtained in step S2 is reacted with a condensation reagent N,N'-carbonyldiimidazole, and after the reaction is completed, the compound 4 is obtained by washing with water, distillation, and column chromatography separation; S4: Deprotection: Compound 4 obtained in step S3 is deprotected by ammonium formate in the presence of ethanol as solvent and 10% palladium on carbon as catalyst. After the reaction is completed, lopinavir impurity T is obtained by filtration, distillation and column chromatography.

3. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: The strong base described in step S1 is any one of sodium hydroxide, potassium hydroxide, and sodium hydride; the benzyl halide is any one of benzyl chloride and benzyl bromide; the recrystallization solvent is any one of methanol, ethanol, isopropanol, ethyl acetate, or any one of a mixed solvent of methanol and water, ethanol and water, isopropanol and water, ethyl acetate and n-hexane, and ethyl acetate and n-heptane.

4. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: The base used for the alkaline condition in step S3 is any one of diisopropylethylamine, triethylamine, pyridine, 4-dimethylaminopyridine, sodium carbonate, and potassium carbonate.

5. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: In step S3, the molar ratio of the compound 3 to the condensation reagent N,N'-carbonyldiimidazole is (2-2.5):

1.

6. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: The purification method of compound 4 in step S3 is column chromatography, and the eluent is n-hexane:ethyl acetate=(5:1)-(1:1).

7. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: The molar ratio of compound 4 to ammonium formate in step S4 is 1:(3-6), and the mass ratio of compound 4 to 10% palladium on carbon is 1:(0.1-0.8).

8. The method for preparing a lopinavir impurity T according to claim 2, characterized in that: The purification method of the lopinavir impurity T in step S4 is column chromatography, and the eluent is n-hexane:ethyl acetate=(5:1)-(1:1).

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