Entecavir alanine amide phenol monophosphate and its medical use

Abstract

The object of the present invention is to provide entecavir alanine amide phenol monophosphate derivatives represented by formula II and non-toxic pharmaceutically acceptable salts thereof: In formula II, X is a halogen, R or -OR; R is an alkyl or substituted alkyl group having 1 to 3 carbon atoms.

Description

Technical Field

[0001] The present invention relates to novel entecavir alanine amide phenol monophosphate derivatives and non-toxic pharmaceutically acceptable salts thereof, and use thereof in preparing anti-hepatitis B virus drugs. Background Art

[0002] Viral hepatitis is a major disease that threatens human health. Entecavir is currently the most effective drug for the treatment of hepatitis B. However, entecavir has a certain degree of cross-resistance with lamivudine, and its efficacy is poor for lamivudine-resistant patients. In addition, like other nucleoside anti-hepatitis B virus drugs, entecavir is prone to rebound after discontinuation of treatment. Animal experimental evaluation results show that entecavir has a certain degree of carcinogenicity.

[0003] As a nucleoside analog, entecavir is phosphorylated in the body to entecavir monophosphate, which is further converted into the active form of entecavir triphosphate, inhibiting the replication of HBV and exerting an anti-HBV effect.

[0004]

[0005] Invention patent CN103804417 discloses a series of entecavir phosphoamido / phenol ester derivatives, and the most active compound I-5-B (Example 7) was found to have a good antiviral effect in duck hepatitis B. Compound I-5-B is enzymatically hydrolyzed in vivo to generate entecavir monophosphate, which is further converted into entecavir triphosphate.

[0006] However, in subsequent development research, we found that in beagles, whose metabolic properties are closer to those of humans, I-5-B cannot be completely converted into an active form, and a relatively high concentration of the prodrug prototype is still present in the plasma, which may cause unexpected toxicity or side effects. Summary of the invention

[0007] The purpose of the present invention is to provide a monophosphate entecavir alanine amide phenol derivative represented by formula II and a non-toxic pharmaceutically acceptable salt thereof:

[0008]

[0009] In formula II, X is H, halogen, R or -OR; R is an alkyl or substituted alkyl group having 1 to 3 carbon atoms.

[0010] The present invention also provides a pharmaceutical composition comprising the entecavir alanine amide phenol monophosphate derivative shown in formula II and its non-toxic pharmaceutically acceptable salt as an active ingredient.

[0011] Finally, the present invention also provides the entecavir alanine amide phenol monophosphate derivative shown in formula II and its non-toxic pharmaceutically acceptable salt, as well as the use of a pharmaceutical composition comprising the entecavir alanine amide phenol monophosphate derivative shown in formula II and its non-toxic pharmaceutically acceptable salt as an active ingredient in the preparation of an anti-hepatitis B virus drug. DETAILED DESCRIPTION

[0012] The present invention can be further described with reference to the following examples; however, these examples should not be construed as limiting the scope of the present invention.

[0013] The compounds of the present invention can be prepared according to the following synthetic route:

[0014]

[0015] According to the method reported in the reference (Ross BS, et al. Synthesis of Diastereomerically Pure Nucleotide Phosphoramidates. J Org Chem, 2011, 76: 8311-8319.), phenyl dichlorophosphate (i) is used as a raw material to react with alanine methyl ester to obtain a phosphoramidophenol ester intermediate (ii); ii is condensed with pentafluorophenol to prepare a key chiral intermediate (S)-2-[(R)-(2-pentafluorophenoxy)-phenoxy-phosphorylamino]propionic acid methyl ester (iii); iii is reacted with entecavir to obtain the target compound II.

[0016] In the reaction formula, X is H, halogen, R or -OR; R is an alkyl substituted alkyl group having 1 to 3 carbon atoms.

[0017] Reference Example 1 Preparation of 2-amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-isopropoxycarbonylethylamino-phenoxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (I-5-B)

[0018]

[0019] 4 g of anhydrous entecavir was dissolved in 80 ml of DMF, cooled to -5°C, and stirred for 10 minutes; then 40 ml of 0.47 mol / L tert-butyl magnesium bromide was added dropwise to the reaction system and stirred at -5°C for 30 minutes. 7.8 g of (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-phenoxy-phosphoramide]-propionic acid isopropyl ester (iii-0, a product of Suzhou Keyuan Pharmaceutical Technology Co., Ltd.) dissolved in 40 ml of THF was added dropwise to the reaction system; after the addition, the temperature was slowly raised to room temperature and stirred for 16 hours. Then 200 ml of dichloromethane was added to the reaction solution, placed in a separatory funnel, washed with saturated brine (2 x 200 ml), the organic layer was separated, and dried over anhydrous sodium sulfate overnight. Filter, concentrate the filtrate under reduced pressure, mix with silica gel, apply to silica gel chromatography column, elute with dichloromethane: methanol: ammonia water (10: 1: 0.1) mixed solvent, collect the desired components, combine them, and evaporate to dryness under reduced pressure to obtain 0.7 g of I-5-B. H NMR spectrum δ (ppm, DMSO-d 6 , 400MHz): 1.13-1.18 (6H, m), 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.7 4(1H,s,br),3.79-3.84(1H,m),4.06-4.10(1H,m),4.21-4.27(2H,m),4.61(1H,s,br ), 4.84-4.92 (1H, m), 5.07 (1H, d), 5.16 (1H, s, br), 5.41 (1H, m), 6.03-6.08 (1H, m), 6 .45(2H,s,br),7.16-7.24(3H,m),7.36-7.40(2H,m),7.66(1H,s),10.57(1H,s,br).

[0020] Example 1 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-phenoxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-1)

[0021]

[0022] Example 1.1 Preparation of (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-phenoxy-phosphoramide]-propionic acid methyl ester (iii-1)

[0023] Referring to the method reported in the literature (Ross BS, et al. Synthesis of Diastereomerically Pure Nucleotide Phosphoramidates. J Org Chem, 2011, 76: 8311-8319.), 6.6 g (0.047 mol) of L-alanine methyl ester hydrochloride was dissolved in 50 ml of anhydrous dichloromethane, cooled to -70°C, and 13.8 ml of triethylamine was added dropwise; then 10 g of phenyl dichlorophosphate dissolved in 40 ml of anhydrous dichloromethane was added dropwise to the reaction system. The reaction system was heated to 0°C within 2 hours and stirred for 1 hour. A solution of 8.7 g of pentafluorophenol and 7.3 ml of triethylamine in 30 ml of anhydrous dichloromethane was added to the reaction mixture within 20 minutes; the reaction mixture was stirred at 0°C for 4 hours, the white solid was filtered out, and the filter cake was rinsed with 20 ml of dichloromethane. The filtrate was evaporated to dryness under reduced pressure, and the residue was recrystallized twice with a mixed solvent of n-hexane / ethyl acetate (4:1) to obtain 3.8 g of white solid iii-1 with a de value of 98.6%. 6 , 400MHz): 1.28 (3H, d), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.23-7.28 (3H, m), 7.40-7.45 (2H, m).

[0024] Example 1.2 Preparation of Compound II-1

[0025] Referring to the method of the reference example, iii-1 was used to replace (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-phenoxy-phosphoramide]-propionic acid isopropyl ester (iii-0) to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-1 with a yield of 15%. H NMR spectroscopy δ (ppm, DMSO-d 6 , 400MHz): 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.75 (1H, s, br) , 3.61 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2H, m), 4.61 ( 1H, s, br), 5.03 (1H, d), 5.16 (1H, s, br), 5.36 (1H, m), 6.01-6.07 (1H, m), 6.39 (2H, s, br), 7.16-7.24 (3H, m), 7.36-7.40 (2H, m), 7.66 (1H, s), 10.55 (1H, s).

[0026] Example 2 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-(4-fluoro-phenyl)oxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-2)

[0027]

[0028] Referring to the method of Example 1.1, dichlorophosphate-(p-fluoro-phenol) ester was used instead of dichlorophosphate phenol ester to react with L-alanine methyl ester hydrochloride and pentafluorophenol to obtain (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-(p-fluorophenoxy)-phosphoramide]-propionic acid methyl ester (iii-2) with a yield of 25% and a de value of 98.2%. H NMR spectrum δ (ppm, DMSO-d 6 , 400MHz): 1.28 (3H, d), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.20 (2H, dd), 7.27 (2H, dd).

[0029] Referring to the method of the reference example, iii-2 was used instead of iii-0 to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-2 with a yield of 13%. H NMR spectroscopy δ (ppm, DMSO-d 6 , 400MHz):: 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.75 (1H, s, br), 3.61 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2H, m), 4.61(1H,s,br),5.03(1H,d),5.16(1H,s,br),5.36(1H,m),6.01-6.07(1H, m), 6.39 (2H, s, br), 7.20 (2H, dd), 7.23 (2H, dd), 7.66 (1H, s), 10.55 (1H, s).

[0030] Example 3 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-(4-chloro-phenyl)oxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-3)

[0031]

[0032] Referring to the method of Example 1.1, dichlorophosphate-(p-chloro-phenol) ester was used instead of dichlorophosphate phenol ester to react with L-alanine methyl ester hydrochloride and pentafluorophenol to obtain (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-(p-chlorophenoxy)-phosphoramide]-propionic acid methyl ester (iii-3) with a yield of 36% and a de value of 98.3%. H NMR spectrum δ (ppm, DMSO-d 6 , 400MHz): 1.28 (3H, d), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.23 (2H, dd), 7.37 (2H, dd).

[0033] Referring to the method of the reference example, iii-3 was used instead of iii-0 to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-3 with a yield of 16%. H NMR spectroscopy δ (ppm, DMSO-d 6 , 400MHz): 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.75 (1H, s, b r), 3.61 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2H, m), 4 .61(1H,s,br),5.03(1H,d),5.16(1H,s,br),5.36(1H,m),6.01-6.07(1H,m ), 6.39 (2H, s, br), 7.23 (2H, dd), 7.42 (2H, dd), 7.66 (1H, s), 10.55 (1H, s).

[0034] Example 4 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-(4-bromo-phenyl)oxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-4)

[0035]

[0036] Referring to the method of Example 1.1, dichlorophosphate-(p-bromo-phenol) ester was used instead of dichlorophosphate phenol ester to react with L-alanine methyl ester hydrochloride and pentafluorophenol to obtain (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-(p-bromophenoxy)-phosphoramide]-propionic acid methyl ester (iii-4) with a yield of 41% and a de value of 98.0%. H NMR spectrum δ (ppm, DMSO-d 6, 400MHz): 1.28 (3H, d), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.23 (2H, dd), 7.41 (2H, dd).

[0037] Referring to the method of the reference example, iii-4 was used instead of iii-0 to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-4 with a yield of 21%. H NMR spectroscopy δ (ppm, DMSO-d 6 , 400MHz): 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.75 (1H, s, b r), 3.61 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2H, m), 4 .61(1H,s,bt),5.03(1H,d),5.16(1H,s,br),5.36(1H,m),6.01-6.07(1H,m ), 6.39 (2H, s, br), 7.21 (2H, dd), 7.48 (2H, dd), 7.66 (1H, s), 10.55 (1H, s).

[0038] Example 5 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-(4-methoxy-phen)oxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-5)

[0039]

[0040] Referring to the method of Example 1.1, dichlorophosphate-(p-methoxy-phenol) ester was used instead of dichlorophosphate phenol ester to react with L-alanine methyl ester hydrochloride and pentafluorophenol to obtain (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-(p-methoxy-phenoxy)-phosphoramide]-propionic acid methyl ester (iii-5) with a yield of 31% and a de value of 98.2%. H NMR spectrum δ (ppm, DMSO-d 6 , 400MHz): 1.28 (3H, d), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.13 (2H, dd), 7.17 (2H, dd).

[0041] Referring to the method of the reference example, iii-5 was used instead of iii-0 to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-5 with a yield of 12%. H NMR spectroscopy δ (ppm, DMSO-d 6 , 400MHz): 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.33 (1H, m), 2.75 (1H, s, bt) , 3.61 (3H, s), 3.70 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2 H, m), 4.61 (1H, s, bt), 5.03 (1H, d), 5.16 (1H, s, bt), 5.36 (1H, m), 6.01-6.07 (1 H, m), 6.39 (2H, s, bt), 7.10 (2H, dd), 7.12 (2H, dd), 7.66 (1H, s), 10.55 (1H, s).

[0042] Example 6 2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-((S)-((S)-1-methoxycarbonylethylamino-(4-methyl-phenyl)oxy-phosphoryl)-oxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one (II-6)

[0043]

[0044] Referring to the method of Example 1.1, dichlorophosphate-(p-methyl-phenol) ester was used instead of dichlorophosphate phenol ester to react with L-alanine methyl ester hydrochloride and pentafluorophenol to obtain (S)-2-[-(S)-(2,3,4,5,6-pentafluoro-phenoxy)-(p-methylphenoxy)-phosphoramide]-propionic acid methyl ester (iii-6) with a yield of 38% and a de value of 98.7%. H NMR spectrum δ (ppm, DMSO-d 6 , 400MHz): 1.28 (3H, d), 2.28 (3H, s), 3.61 (3H, s), 3.96-4.06 (1H, m), 6.91-6.97 (1H, m), 7.12 (2H, dd), 7.20 (2H, dd).

[0045] Referring to the method of the reference example, iii-6 was used instead of iii-0 to react with anhydrous entecavir, and the reaction product was separated by silica gel column chromatography to obtain compound II-6 with a yield of 19%. H NMR spectroscopy δ (ppm, DMSO-d 6, 400MHz): 1.24 (3H, d), 2.04-2.09 (1H, m), 2.26-2.31 (4H, m), 2.75 (1H, s, br) , 3.61 (3H, s), 3.85-3.91 (1H, m), 4.07-4.11 (1H, m), 4.21-4.27 (2H, m), 4.61 ( 1H, s, bt), 5.03 (1H, d), 5.16 (1H, s, br), 5.36 (1H, m), 6.01-6.07 (1H, m), 6.39 (2H, s, bt), 7.06-7.21 (4H, m), 7.36-7.40 (2H, m), 7.66 (1H, s), 10.55 (1H, s).

[0046] Example 7 Evaluation of metabolic stability of human plasma and human liver microsomes

[0047] Example 7.1 Evaluation of human plasma stability

[0048] In 1 ml containing 5 mM MgCl 2 Add 2 μl of 50 mM DMSO solution of the test compound to human plasma and keep warm at 37°C. Take 100 μl of the sample at different time points, add 200 μl of methanol, and centrifuge at 14000 rpm for 30 min at 4°C. Take 100 μl of the supernatant, add 100 μl of methanol, and freeze at -20°C for later use.

[0049] Example 7.2 Evaluation of metabolic stability of human liver microsomes

[0050] In 1 ml containing 5 mM MgCl 2 , 50 mM K 2 HPO 4 Add 2 μl of 50 mM DMSO solution of the test compound to a buffer solution (pH 7.4), then add human liver S9 fraction to 4 mg / ml, and keep warm at 37°C. Take 100 μl of samples at different time points, add 300 μl of methanol, and centrifuge at 14000 rpm for 30 min at 4°C. Take 100 μl of the supernatant, add 100 μl of methanol, and freeze at -20°C for later use.

[0051] LC-MS / MS was used to determine the content of the test compound in plasma or liver microsomes and calculate the half-life. Instrument: Shimadzu Prominence 20 A liquid chromatograph, Applied Biosystems API 4000 Q-TRAP mass spectrometer; Mass spectrometry conditions: ESI negative ion detection; Chromatographic column: Diamonsil C 18(100×4.6mm, 5μm) chromatographic column; column temperature: 40℃; flow rate: 0.5ml / min. Mobile phase A: methanol; mobile phase B: 5% methanol aqueous solution (containing 2mM ammonium formate), flow rate 0.5ml / min, gradient elution is shown in the following table:

[0052]

[0053] The measurement results are shown in Table 1:

[0054] Table 1 Stability of human plasma and liver microsomes

[0055]

[0056] Example 9 Pharmacokinetic Evaluation in Rats

[0057] SD rats, weighing 180 to 220g, 6 rats per group, half male and half female; fast for 12 hours before administration. Add the test compound to 0.5% sodium carboxymethylcellulose solution, mix well, and administer by gavage (dosage is 100μmol / kg). Blood is collected from the jugular vein before and 0.25h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 10h, 12h, 24h after administration, 0.3ml / time, anticoagulated with sodium heparin, centrifuged to separate plasma, and stored at -80℃ for determination.

[0058] Take 50 μL of drug-containing plasma, add 50 μL of methanol, 100 μL of internal standard acetaminophen methanol solution, vortex for 1 min, centrifuge at 4°C 12000 rpm for 10 min, take the supernatant and perform LC-MS / MS quantitative analysis in an inner tube (the method is the same as Example 7). WinNonlin 6.3 pharmacokinetic software was used, and the non-compartmental statistical moment method was selected to calculate the pharmacokinetic parameters of entecavir in the blood. The results are shown in Table 2:

[0059] Table 2 Pharmacokinetic evaluation results in rats

[0060]

[0061] Example 10 Pharmacokinetic Evaluation in Beagle Dogs

[0062] Male beagle dogs (7-8 months old, weighing 7-10kg) were randomly divided into groups of 2 and weighed. Fasting for 12 hours before administration. The samples to be tested at a certain concentration were ground and suspended in a 0.5% sodium carboxymethylcellulose solution, and II-1 (5mg / kg), II-6 (5.13mg / kg) or I-5-B (5.27mg / kg) were administered by gavage. Blood was collected from the cephalic vein of the forelimbs before administration and 0.5h, 1h, 2h, 4h, 6h, 8h, 10h, and 24h after administration, 0.5ml / time, anticoagulated with sodium heparin, and the plasma was separated by centrifugation and stored at -80℃ for determination.

[0063] Take 50 μL of drug-containing plasma, add 50 μL of methanol, 100 μL of internal standard acetaminophen methanol solution, vortex for 1 min, centrifuge at 4°C 12000 rpm for 10 min, take the supernatant and perform LC-MS / MS quantitative analysis in the inner tube (the method is the same as Example 7). WinNonlin 6.3 pharmacokinetic software was used to select the non-compartmental statistical moment method to calculate the pharmacokinetic parameters of entecavir or prodrug prototype in the blood after administration of the target compound. The maximum blood drug concentration is shown in Table 3:

[0064] Table 3 Maximum blood concentrations of prodrug prototype and entecavir

[0065]

[0066] Example 11 Beagle dog tissue distribution evaluation

[0067] Male beagle dogs (7-8 months old, weighing 7-10kg) were randomly divided into groups of 4 and weighed. The samples to be tested at a certain concentration were ground and suspended in a 0.5% sodium carboxymethylcellulose solution, and H-1 (dose: 5mg / kg) or I-5-B (dose: 5.27mg / kg) sodium carboxymethylcellulose suspension was administered by gavage once a day for 4 consecutive days. After the last administration, the animals were fasted but not watered for 4 hours, anesthetized with pentobarbital, and the organs were removed, irrigated with ice saline, and frozen in liquid nitrogen for later use.

[0068] Take frozen tissue, add 3 times the amount of frozen 70% methanol (containing 20mM EDTA / EGTA), prepare homogenate, centrifuge at 4℃12000rpm for 10min, take the supernatant and put it into the inner tube for LC-MS / MS quantitative analysis to determine the content of entecavir triphosphate in each tissue. Instrument: TSQ Quantum liquid chromatography-mass spectrometry (LC / MS / MS) of Finnigan Company, USA, composed of Finnigan Surveyor LC pump, Surveyor AS autosampler, electrospray ionization source (ESI) and three-stage tandem mass spectrometer. The control software is Xcalibur 1.4, and the mass spectrometry data analysis uses Lcquan 2.0 data processing system. The chromatographic column was a Discovery ODS column (250 mm × 4.6 mm, 5 μm), a C18 guard column (4 mm × 3.0 mm), the mobile phase was methanol-water-formic acid (10-30:90-70:0.5, V / V / V), the flow rate was 0.7 ml / min; the injection volume was 20 μl; and the column temperature was room temperature.

[0069] The measurement results are shown in Table 4:

[0070] Table 4 Entecavir triphosphate content in various organs (ng / g)

[0071]

Claims

1. Entecavir alanine amide phenol monophosphate derivatives represented by formula II and non-toxic pharmaceutically acceptable salts thereof: In formula II, X is H.

2. A pharmaceutical composition comprising the entecavir alanine amide phenol monophosphate derivative and its non-toxic pharmaceutically acceptable salt as claimed in claim 1 as an active ingredient.

3. The pharmaceutical composition of claim 2, which is in the form of capsules, tablets, granules, powders, suspensions, solutions or lozenges.

4. Use of the entecavir alanine monophosphate derivative and its non-toxic pharmaceutically acceptable salt as claimed in claim 1, and a pharmaceutical composition comprising the entecavir alanine monophosphate derivative and its non-toxic pharmaceutically acceptable salt as claimed in claim 1 as an active ingredient in the preparation of an anti-hepatitis B virus drug.

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