HK1081190A - Preparation of [1s-[1a,2b,3b,4a(s*)]]-4-[7-[[1-(3-chloro-2-thienyl) methyl]propyl]amino]-3h-imidazo[4,5-b]pyridii - Google Patents

Description

Intermediate for preparing cyclopentane formamide compound and preparation method thereof

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Technical Field

The present invention relates to a process for the preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide, compound I, a process for the preparation of intermediates thereof, and said intermediates.

The compounds I are suitable for use as cardiovascular agents, more particularly as antihypertensive and anti-ischemic agents, as cardioprotective agents for improving the area of myocardial infarction after ischemic injury or myocardial ischemia, and as anti-lipolytic agents for lowering plasma lipid levels, serum triglyceride levels, and plasma cholesterol levels.

For example, U.S. p.5364862 discloses the use of compound I and related compounds as antihypertensive and anti-ischemic agents, and U.S. p.5561134 discloses their use as cardioprotective and anti-lipolytic agents.

Correlated progression

Methods for preparing compound I, its related compounds and intermediates are disclosed by Spada et al, u.s.p.5364862 and u.s.p.5561134, published by 1994.11.15.

The preparation method of the present invention can improve yield, purity, ease of preparation and/or isolation of intermediates and final products, and can provide industrially more applicable reaction conditions and operability, compared to previously disclosed preparation methods.

Summary of The Invention

The present invention relates to a process for the preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide, compound I, a process for the preparation of intermediates thereof, and said intermediates themselves.

Detailed Description

Preferred embodiments of the present invention are illustrated in schemes I, II, III and IV.

Scheme I

Scheme II

Scheme III

One embodiment of the present invention relates to a process for the preparation of compound I, which process comprises reacting [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- [ 3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (compound IX), with formamidine acetate, or with the orthoformate or dimethylformamide dimethyl formamide dimethyl acetal, optionally in the presence of a catalytic amount of an inorganic or organic acid. Preferably, the reaction is carried out in an organic solvent, or a mixture of organic solvents, water, or an organic solvent or a mixture of several organic solvents and water. In a particular embodiment of the process according to the invention, it is preferred that the reaction is carried out with formamidine acetate in n-butyl acetate. In another particular embodiment of the process according to the invention, the reaction is preferably carried out with triethyl orthoformate in the presence of a catalytic amount of an inorganic or organic acid, preferably hydrochloric acid or camphorsulfonic acid.

A preferred embodiment of the present invention relates to a process for the preparation of compound I, preferably in its crystalline form, comprising the steps of forming the free base of compound IX from its dihydrochloride salt and then reacting said free base with formamidine acetate, which steps are performed in a catenated manner without intermediate isolation and purification of the free base of compound IX.

A more preferred embodiment of the present invention is directed to a process for the preparation of compound I in crystalline form, which comprises reacting the dihydrochloride salt of compound IX with formamidine acetate without first forming the free base of compound IX.

Another embodiment of the present invention relates to a process for the preparation of said compound IX, which process comprises hydrolysing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (compound VIII), preferably in the presence of an organic solvent, or a mixture of organic solvents, and an aqueous inorganic or organic acid. Examples of suitable organic solvents include methanol, ethanol, isopropanol, ethyl acetate, toluene, tetrahydrofuran, tetrahydropyran, and dioxane. In a particular embodiment of the process of the invention, the preferred solvent is methanol, or a mixture of toluene and isopropanol. In a particular embodiment of the process of the invention, the preferred mixture in which compound VIII is hydrolyzed to give compound IX is tetrahydrofuran and aqueous hydrochloric acid, methanol, ethanol or isopropanol and aqueous hydrochloric acid or ethyl acetate and isopropanol and aqueous hydrochloric acid.

Another embodiment of the present invention relates to a process for the preparation of said compound VIII, which process comprises reducing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (compound VII), preferably in the presence of an organic solvent or a mixture of an organic solvent and water. Examples of suitable organic solvents include methanol, ethanol, isopropanol, ethyl acetate, tetrahydrofuran, tetrahydropyran, and dioxane. In a particular embodiment of the process of the invention, the preferred solvent is methanol.

Preferably, the reduction is carried out at a temperature in the range of about 20 to about 90 ℃; more preferably at the reflux temperature of the system in which the reduction is carried out. In a particular embodiment of the invention, the preferred temperature is about 65 ℃ or the reflux temperature of the reduction system carried out in methanol.

The reduction of compound VII to compound VIII is carried out in the presence of reducing agents well known in the art or described herein. Reducing agents suitable for reduction include potassium borohydride in the presence of copper (I) chloride, aqueous solutions of iron and hydrochloric acid, zinc and calcium chloride, platinum on carbon or palladium on carbon in the presence of hydrogen, platinum on carbon in the presence of ammonium formate, zinc powder in the presence of ammonium acetate, and platinum on sulfided carbon in the presence of ammonium formate. In a particular embodiment of the process of the invention, the preferred reducing agent is platinum on water-wet carbon, or zinc powder in the presence of a substance which can transfer hydrogen to the nitro group to be reduced, preferably ammonium acetate, or platinum on carbon in the presence of hydrogen.

Another embodiment of the present invention relates to a process for the preparation of said compound VII, which comprises reacting (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine (compound V) with 2R, 3S-isopropylidenedioxy-4R-amino-1S-ethylamino-carbonyl-cyclopentane (compound VI), preferably in the presence of an aprotic organic solvent. Aprotic organic solvents suitable for use in the process include aprotic organic ethers, aromatic hydrocarbons, heteroaromatic hydrocarbons, aliphatic hydrocarbons and aprotic organic amides. In a particular embodiment of the process of the invention, the preferred organic solvent is toluene.

According to the invention, the reaction of compound V with compound VI is carried out in the presence of a base. Suitable bases for this reaction include aqueous alkali metal hydroxide, aqueous alkali metal carbonate, aqueous alkali metal bicarbonate, and aprotic organic amines. In a particular embodiment of the process of the invention, the preferred base is potassium carbonate.

Another embodiment of the present invention relates to a process for the preparation of said compound V, which comprises replacing the hydroxyl moiety in (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine (compound IV) with chloro groups, preferably in the presence of an aprotic organic solvent. Aprotic organic solvents suitable for this reaction include aprotic organic ethers, aromatic hydrocarbons, heteroaromatic hydrocarbons, aliphatic hydrocarbons and aprotic organic amides. In a particular embodiment of the process of the invention, the preferred organic solvent is toluene. Reagents suitable for carrying out the displacement include oxalyl chloride, phosphorus trichloride, phosphorus pentachloride, thionyl chloride and phosphorus oxychloride. In a particular embodiment of the process of the invention, the preferred reagent is phosphorus oxychloride.

Another embodiment of the present invention relates to a process for the preparation of said compound IV, which comprises reacting 4-chloro-3-nitropyridin-2 (1H) -one (compound II) with (R) -3-chloro-a-ethyl-2-thiopheneethylamine (compound III), preferably in the presence of an organic solvent or a mixture of several organic solvents, water, or a mixture of an organic solvent or several organic solvents and water. Examples of suitable organic solvents include methanol, ethanol, isopropanol, ethyl acetate, tetrahydrofuran, tetrahydropyran, and dioxane. Examples of preferred solvents include methanol, ethanol, isopropanol, and mixtures of methanol, ethanol or isopropanol with water.

According to the invention, the reaction of the compounds II with the compounds III is carried out in the presence of a base. Suitable bases for this reaction include aqueous alkali metal hydroxide, aqueous alkali metal carbonate, aqueous alkali metal bicarbonate, and aprotic organic amines. In a particular embodiment of the process of the invention, the preferred base is N, N-diisopropylethylamine.

Another embodiment of the present invention is directed to a process for the preparation of said compound II, which comprises reacting 4-hydroxy-3-nitro-2 (1H) pyridone (compound XII) with phosphorus oxychloride or thionyl chloride, preferably phosphorus oxychloride, in the presence of an organic solvent and a base. Suitable organic solvents for this reaction include aprotic organic ethers, aromatic hydrocarbons, heteroaromatic hydrocarbons, aliphatic hydrocarbons, halogenated hydrocarbons and aprotic organic amides. Examples of suitable organic solvents include toluene, methyl tert-butyl ether, dimethylformamide, ethyl acetate, butyl acetate, 1-methyl-2-pyrrolidone, chloroform, and methylene chloride. In a particular embodiment of the process of the invention, the preferred organic solvent is toluene. In a particular embodiment of the process of the invention, the preferred base is N, N-diisopropylethylamine.

Another embodiment of the present invention is directed to a process for the preparation of compound XII which comprises hydrolyzing and decarboxylating 2-hydroxy-3-cyano-4-methoxypyridine to obtain 2, 4-dihydroxypyridine, followed by nitration of said 2, 4-dihydroxypyridine. In a particular embodiment of the process of the invention, the hydrolysis, decarboxylation and nitration are carried out in a concatenated manner without intermediate isolation and purification of the 2, 4-dihydroxypyridine, preferably by heating the 2-hydroxy-3-cyano-4-methoxypyridine sequentially with concentrated phosphoric acid, then glacial acetic acid, then nitric acid.

A preferred embodiment of the present invention is directed to a process for the preparation of the dihydrochloride salt of compound IX, which comprises the steps of reacting compound II with compound III to form compound IV, then replacing the hydroxyl moiety of compound IV with a chlorine group to form compound V, then reacting compound V with compound VI to form compound VII, then reducing compound VII to form compound VIII, and then hydrolyzing compound VIII in the presence of hydrochloric acid, said steps being performed in a catenated fashion without intermediate isolation and purification of intermediate compounds VIII, VII, V or IV.

It is clear to those skilled in the art that hydroxypyridine may exist in the form of the tautomeric pyridone, which may exist in the form of the tautomeric hydroxypyridine. Thus, compounds II, III, X, XI and XII may be present as the corresponding hydroxypyridine or pyridone, or as a mixture of the two forms.

The present invention will be further described below in detail, but it is not limited to the following examples.

Example 1

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

[1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound IX) dihydrochloride monohydrate (20g) was suspended in water (120ml), and the mixture was heated to 65 ℃ to give a solution. Butyl acetate (84.7g) was added followed by a solution of sodium carbonate (15.2g) in water (54 g). The mixture was stirred at 55 ± 5 ℃ for about 10 minutes, then the layers were separated and the organic layer was washed with brine. Formamidine acetate (10.3g) was added to the organic layer and the mixture was stirred at 85. + -. 5 ℃ for about 2 hours. The mixture was cooled to 55 ±, washed with 5% sodium bicarbonate solution and then with water. Water (1.2g) was added to the organic layer at 55. + -. 5 ℃ and the mixture was cooled to 21. + -. 2 ℃ over about 2 hours. The mixture was stirred for 12 to 24 hours, filtered, the solid material was washed with butyl acetate and dried under vacuum at 52 ℃ for about 24 hours under nitrogen purge to give [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (compound I) in the form of a hydrate, which contained about 1.7% (w/w) of water.

¹HNMR(200Mhz，DMSO)δ0.915(3H，t)；1.4(3H，t)；3.2-3.0(4H，m)；4.91(1H，d)；6.3(1H，d)；6.6(1H，bd)；6.9(1H，d)；7.4(1H，d)；7.8(1H，d)；8.05(1H，bt)；8.2(1H，s).

Example 2

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

N-butyl acetate (54.3g) and formamidine acetate (4.5g, 43mmol) were combined at room temperature. The mixture was heated to 100 ℃ and [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- [ 3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (compound IX) dihydrochloride monohydrate (8.4g, 15mmol) was added over 21 minutes. The mixture was stirred at 100 ℃ for 1 hour, then cooled to 80 ℃ and 8% W/W aqueous sodium bicarbonate solution (90ml) was added. The mixture was stirred for 5 minutes and then the layers were separated. The organic layer was washed with water (45g) (maintained at 60 ℃ C. or higher). The organic layer was then treated with activated carbon (0.42g) and stirred at 75 ℃ for 45 minutes. The reaction was filtered and the filtrate was cooled to 22 ℃ over 1 hour. The mixture was stirred at 22 ℃ for 2 hours, and the resulting solid was filtered and washed with n-butyl acetate (6 ml). The collected white solid was dried under vacuum at 50 ℃ under a stream of nitrogen overnight to give mixture I.

Example 3

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

N-butyl acetate (25.2g) and formamidine acetate (2.81g, 27mmol) were combined at room temperature. The mixture was heated to 100 ℃ and a room temperature slurry of the dihydrochloride monohydrate of Compound IX (8.4g, 15mmol) in n-butyl acetate (30.6g) was added over 11 minutes at 94-100 ℃ and rinsed with n-butyl acetate (9.0g) to completely transfer the slurry. The mixture was stirred at 100 ℃ for 30 minutes. The mixture was cooled to 80 ℃ and 8% W/W aqueous sodium bicarbonate solution (90ml) was added. The mixture was stirred for 5 minutes and then the layers were separated. The organic layer was washed with water (45g) (maintained at 60 ℃ C. or higher). The organic layer was then treated with activated carbon (0.42g) and stirred at 75 ℃ for 45 minutes. The reaction was filtered and then cooled to 22 ℃ over 1 hour. The mixture was stirred at 22 ℃ for 2 hours and the resulting solid was collected by filtration and washed with n-butyl acetate (5ml) to give compound I.

Example 4

Preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-H-cyclopenta-1, 3-dioxole-4-carboxamide (Compound III)

[3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (compound VII) (12.4g), methanol (32.4g), and 5% platinum on carbon (water wet, 62.4% assay) (9.6g) were mixed. The mixture was degassed with nitrogen and ammonium formate (10.0g) was added. The mixture was heated at about 65 ℃ for 4h, cooled to 23 ℃ and filtered through a filter aid (SulkaFloc 300) rinsing with ethyl acetate (180.4 g). The filtrate was washed with 5% aqueous sodium bicarbonate (50ml) and then with half-saturated aqueous sodium chloride. The organic layer was evaporated in vacuo at 50 ℃ to give compound VIII as a foam which was used in the following reaction without further treatment.

Example 5

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound IX)

Compound VIII (11.2g) was mixed with tetrahydrofuran (160g) and concentrated hydrochloric acid (7.8ml) was added over 2 minutes. The mixture is stirred for 15 hours, then cooled to 0-3 ℃ and stirred for another 1 hour. The mixture was filtered and the solid washed with cold (0-3 ℃) methyl tert-butyl ether and then dried under vacuum at 55 ± 5 ℃ for 48 hours under nitrogen purge to give compound IX as the dihydrochloride monohydrate salt, melting point: 135 deg.C; MS (EI), m/z 467 (50%),

¹HNMR(500Mhz，DMSO)δ0.91(1H，t)；1.05(1H，t)；1.55(2H，m)；2.39(1H)；3.11(1H)；4.01(2H)；6.24(1H)；6.36(1H)；6.98(1H)；7.37(1H)；7.48(1H)；12.47(1H).

example 6

Preparation of (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine (Compound IV)

To a 3-neck 1-liter round bottom flask equipped with a mechanical stirrer, thermocouple, nitrogen inlet and condenser were added sequentially: 14.5g of (R) -3-chloro-a-ethyl-2-thienylethylamine (compound III), 10.9g of 4-chloro-3-nitropyridin-2 (1H) -one (compound II), 35g of 2-propanol (IPA) and 25ml of N, N-Diisopropylethylamine (DIPEA). The mixture was stirred at 70 + -2 deg.C for 7 hours, then the reaction was cooled overnight to room temperature (22 + -3 deg.C). The mixture was concentrated to 41.4g of a syrup, which was then dissolved in 425ml of ethyl acetate. The solution is washed with 125ml of water, 2X 50ml of a 5N solution of ammonium chloride and 2X 50m ] saturated sodium chloride solution and then dried over sodium sulfate. The solution was filtered, concentrated, and the resulting solid material was collected by filtration to give compound IV, melting point: 150 to 152 ℃. Mass Spectrometry (EI), m/z 328 (6%),

¹HNMR(500Mhz，DMSO)δ0.91(3H，t)；1.8-1.6(2H，m)；3.1(1H，m)；3.95(1H，m)；5.9(1H，d)；7.0(1H，d)；7.3(1H，dd)；7.5(1H，d)；8.8(1H，d)；11.1(1H).

example 7

Preparation of (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine (Compound V)

(R) N- [1- [ (3-chloro-2-thienyl) methyl group containing 2 equivalents of DIPEA hydrochloride]Propyl radical]A toluene solution of (0.1mol in 100ml of toluene) of (E) -2-hydroxy-3-nitro-4-pyridylamine (compound IV) was heated to 60 ℃ and 20.6g of phosphorus oxychloride were added over 10 minutes with stirring. The reaction was stirred at 60 ℃ until the reaction was complete (3 hours). After cooling to 0 ℃ 245g of 2N sodium chloride were added at a rate to maintain the reaction temperature below 10 ℃. The mixture in two phases is stirred at 0 ℃ for 1-2 hours and then allowed to warm to room temperature overnight. The bottom aqueous layer was separated from the organic layer. The organic layer was concentrated in vacuo and the residue was purified by flash chromatography (flash chromatography) eluting with 25: 75 ethyl acetate/heptane to afford compound V. MS (EI), m/z 345 (10%).¹HNMR(500Mhz，CDCl₃/CD₃OD)δ1.0(3H，t)；1.5-1.8(2H，m)；2.9-3.2(2H，m)；3.8(1H，m)；6.5(1H，bd)；6.6(1H，d)；7.15(1H，d)；7.9(1H，d).

Example 8

Preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (Compound VII)

To (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl group]Propyl radical]28.5g of 325 mesh potassium carbonate are added continuously to a toluene solution (0.1mol in 100ml toluene) of (E) -3-nitro-4-pyridylamine (compound V), followed by 33.7g of 2R, 3S-isopropylidenedioxy-4R-amino-1S-ethylamino-carbonylcyclopentane (compound VI) in one portion. The suspension was heated to 98. + -. 2 ℃ for 6 hours. At the end of the reaction the suspension was cooled to room temperature and 230g of water were added with stirring. The aqueous layer was removed, and a 14.5 w/w% ammonium chloride solution was added to the organic layer with stirring, and then the bottom aqueous layer was removed again. 100g of water were added and the layers were separated again. The toluene solution was concentrated in vacuo and the residue was purified by flash chromatography using 60: 40: 5 ethyl acetate/heptane/triethylamine as eluent to afford compound VII. Mass Spectrometry (FAB-LRP), (M + H)⁺538(100％)，

¹HNMR(500Mhz，CDCl₃)δ1.0(3H，t)；1.15(3H，t)；1.6(1H.m)；1.75(1H，m)；2.6(1H，m)；2.8(1H，m)；3.1，(2H，m)；3.35(2H，m)5.95(1H.d)；6.85(1H，d)；7.1(1H，d)；7.8(1H，d)；9.25(1H，d)；9.55(2H，d).

Example 9

Preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (Compound VIII)

To a solution of compound VII in toluene (0.09mol in 85ml of toluene) was added 24g of methanol, 18g of IPA and 54g of ammonium acetate with stirring (15 min). Then 35g of powdered zinc metal were added in small portions (until no exotherm occurred) while keeping the temperature of the reactants below 40 ℃. After the addition of zinc was complete, the reaction mixture was stirred at 40 ℃ for 30 minutes and then the heterogeneous mixture was cooled to 0 ℃. The grey salt was filtered at 0 ℃ and washed with toluene. The filtrate is concentrated in vacuo and the residue is purified by flash chromatography using 90: 10: 5 ethyl acetate/heptane/triethylamine as eluent to afford compound VIII. MS (M + H)⁺508(100％)，¹HNMR(500Mhz，DMSO)δ0.9(3H，t)；1.0(3H，t)；1.7-1.4(3H，m)；2.35(1H，m)；2.95(2H，m)；3.1，(2H，m)；5.75(1H，d)6.0(1H.d)；7.0(1H，d)；7.25(1H，d)；8.15(1H，m).

Example 10

Preparation of a interlinked product of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- [ 3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound IX)

To a 3-neck 1-liter round bottom flask equipped with a mechanical stirrer, thermocouple, nitrogen inlet and condenser were added sequentially: 23.3g of (R) -3-chloro-a-ethyl-2-thienylethylamine (compound III) hydrochloride, 18.0g of 4-chloro-3-nitropyridin-2 (1H) -one (compound II), 35g of 2-propanol (IPA) and 33.3g N, N-Diisopropylethylamine (DIPEA). The mixture is stirred while heated to 70 + -2 deg.C for 5-7 hours. The reaction was then allowed to cool overnight to room temperature (22. + -. 3 ℃). 240g of toluene was added to the reaction in the morning, and IPA/toluene was azeotropically removed by distillation at 80-90 ℃ under reduced pressure. Residual IPA was detected by gas chromatography.

When the IPA content is below 0.1%, the resulting liquid/liquid two-phase mixture containing (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine (compound IV) is cooled to 60 ℃ and 20.6g of phosphorus oxychloride are added over 10 minutes with stirring. The reaction was stirred at 60 ℃ until the reaction was complete (2-3 hours), then cooled to 0 ℃ and 245g of 2N aqueous sodium hydroxide solution was added at a rate to maintain the reaction temperature below 10 ℃. The two-phase mixture was stirred at 0 ℃ for 1-2 hours and then allowed to warm to room temperature overnight.

In the morning, the bottom aqueous layer was separated from the organic layer containing (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine (compound V), and 28.5g of 325 mesh potassium carbonate followed by 33.7g of 2R, 3S-isopropylidenedioxy-4R-amino-1S-ethylamino-carbonyl-cyclopentane (compound VI) were added in one portion to the organic layer. The suspension is heated to 98 + -2 ℃ for 2-6 hours. When the reaction was complete, 230g of deionized water was added with stirring. The aqueous layer was removed, and a 14.5 w/w% aqueous ammonium chloride solution was added to the organic layer with stirring, and then the bottom aqueous layer was removed again. 100g of deionized water was added and the layers were separated again.

To a solution of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (compound VII) in toluene was added 24g of methanol, 18g of IPA and 54g of ammonium acetate with stirring (15 minutes). Then 35g of powdered zinc metal were added in small portions (until no exotherm occurred) while keeping the temperature of the reactants below 40 ℃. After the addition of zinc was complete, the reaction mixture was stirred at 40 ℃ for 30 minutes and then the heterogeneous mixture was cooled to 0 ℃. The grey salt was filtered and washed with toluene. The filtrate ([3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide (compound VIII) in toluene) was used directly for the next reaction.

To a toluene solution of compound VIII was added 100g IPA and the mixture was stirred while it was heated to 50 ± 3 ℃. 31g of concentrated hydrochloric acid were added slowly over a few minutes. When compound VIII was consumed, the reaction temperature was lowered to 22 ± 3 ℃ and stirred overnight. In the morning, the suspension is cooled to 0 ℃ and 45g of ethyl acetate are added. After stirring at this temperature for 1 hour, the solid was filtered and washed sequentially with cold (0 ℃) IPA and room temperature ethyl acetate. The nearly pure white filter cake was dried under vacuum at 40 + -3 deg.C for 10 hours to give [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide as the dihydrochloride monohydrate. Melting point: 135 ℃ is adopted.

Example 11

Preparation of 4-chloro-3-nitropyridin-2 (1H) -one (Compound II)

To 150ml of a flask2, 4-dihydroxy-3-nitropyridine (Compound XII) (10.0g, 0.064mol) and toluene (30ml) were added to the flask. The mixture was stirred at a moderate rate and heated to 47 ℃. Phosphorylchloride (POCl) was added over 10 minutes by syringe pump₃) (4.4g, 0.0289mol), the temperature rose to 49 ℃ due to the exotherm. N, N-Diisopropylethylamine (DIPEA) (2.22g, 0.017mol) was added over 10 minutes and the temperature rose to 51 ℃ due to the exotherm. Another portion of POCl was added over 10 minutes₃(4.4g, 0.0289mol) followed by another portion of DIPEA (2.22g, 0.017mol) over 10 minutes. A third portion of POCl was added over 10 minutes₃(4.4g, 0.0289mol), then a third portion of DIPEA (2.22g, 0.017mol) was added over 10 minutes followed by a final portion of POCl over 10 minutes₃(4.4g, 0.0289mol) (POCl added in total)₃17.7g) followed by the final portion of DIPEA (2.22g, 0.017mol) over 10 minutes (8.9g total DIPEA added). The reaction was then stirred at 50 ℃ for 5 hours until IPC indicated that compound XII had been consumed. The reaction was cooled to 20 ℃ over 30 minutes and 50ml water was added over 1.5 hours to raise the temperature to 47 ℃. The mixture was stirred for 4 hours while cooling to 25 ℃. The mixture was filtered and washed twice with 15ml of water and then twice with 15ml of toluene. The product was dried to give compound II.

Example 12

Preparation of 2, 4-dihydroxy-3-nitropyridine (Compound XII)

In a 500ml flask equipped with mechanical stirring and reflux condenser, 86% phosphoric acid (90ml, 151.3g) and 3-cyano-4-methoxy-2 (1H) pyridone (Compound X) (30.0g, 0.2mol) were mixed under argon. The mixture is heated in an oil bath at 175-180 ℃ for 23 hours. The reaction mixture was cooled to 71 ℃ and glacial acetic acid (90ml, 94.5g) was added and the mixture was then heated at 90 ℃ for about 90 minutes. Fuming nitric acid (density 1.52) (12.6g, 8.3ml) was added carefully over 15 minutes (with a mild exotherm) and the mixture was heated at 90-95 ℃ for 2 hours. Water (90ml) was then added to the mixture and heating was continued at 90 ℃ for 1 hour. The mixture was then slowly cooled to room temperature with stirring, filtered through a sintered glass funnel and the residue washed with water to give compound XII, melting point: 268 ℃; nmr (dmso) δ 7.44(1H, d); 6.0(1H, d); 3.5 (2H).

Example 13

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound IX)

To a nitrogen blanketed 3-neck round-bottom flask were added 5% Pt/C (Degussa type F101 RA/W, 21.6g, 2.71mmol), ammonium formate (34g, 543mmol), a solution of compound VII in ethyl acetate (110ml containing 29g of compound VII, 54.3mmol) and methanol (66g) sequentially with mechanical stirring. The black suspension was heated at 60 ℃ for 6 hours, cooled to room temperature and filtered through celite to remove insoluble material. The filter cake was washed with 2X 50ml of ethyl acetate. To the combined filtrates was added concentrated hydrochloric acid (40ml) with stirring over a few minutes, and the mixture was stirred at room temperature for 3 hours. After filtration, drying at 50 ℃ in a vacuum oven gives compound IX as a nearly pure white solid, the dihydrochloride monohydrate.

Example 14

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound IX)

To a 500ml Paar bottle, 1.8g of platinum on 5% carbon (Aldrich, wet, Degussa F101 RA/W), and a solution of compound VII in toluene (8.9g, 16.6mmol, 50g toluene) were added. The mixture was shaken at room temperature under a pressure of 52PSI of hydrogen for 15 hours. The black slurry was filtered through celite to provide a solution of compound VIII. To the solution were added 2-propanol (20g), toluene (57g) and concentrated hydrochloric acid (7.4g) in this order at 20 ℃ and the solution was heated to 45 ℃ with mechanical stirring. After 2 hours at this temperature, the tan precipitate was filtered and washed with 20ml 2-propanol. The filter cake was dried at 45 ℃ for 6 hours to give compound IX as the dihydrochloride monohydrate.

Example 15

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin ] -3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

To a 3-neck round-bottom flask equipped with a condenser and a magnetic stir bar were added compound IX as the dihydrochloride monohydrate (2.2g, 3.9mmol) and deionized water (12g) sequentially. The suspension was heated to 65 ℃ and an aqueous solution of sodium carbonate (1.7g Na) was added thereto₂CO₃In 5g of deionized water, heat to 65 ℃). The organic phase was separated as a light brown oil. Triethyl orthoformate (6.8ml, 41mmol) was then added to the mixture of the two phases and the bottom aqueous layer was removed. After addition of concentrated hydrochloric acid (90ul), it was heated at 80 ℃ for 5 hours. The solution was cooled to 70 ℃, n-butyl acetate (10ml) was added and the organic layer was washed with saturated sodium carbonate, then water and then brine. The organic layer was cooled to room temperature and stirred for 16 hours. After filtration, drying in a vacuum oven at 50 ℃ gives compound I.

Example 16

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

To a 3-neck round-bottom flask equipped with a condenser and a magnetic stir bar were added compound IX as the dihydrochloride monohydrate (2.0g, 3.6mmol) and deionized water (12g) sequentially. The suspension was heated to 65 ℃ and an aqueous solution of sodium carbonate (1.6g Na) was added thereto₂CO₃In 5g of deionized water, heat to 65 ℃). Triethyl orthoformate (9.0ml, 54.3mmol) was then added to the mixture of the two phases and the bottom aqueous layer was removed. The organic layer was washed with deionized water (5ml) and the bottom layer was removed again. After addition of (1R) - (-) -10-camphorsulfonic acid (42mg, 0.18mmol), the solution was taken up in 8Heating at 0 deg.C for 2 hr, and heating at 25 deg.C for 15 hr. The reaction mixture was heated to 70 ℃ again, n-butyl acetate (10ml) was added, and the organic layer was washed with saturated sodium carbonate, then water, and then brine. The organic layer was cooled to room temperature and stirred for 16 hours. After filtration, drying in a vacuum oven at 50 ℃ gives compound I.

Example 17

Preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [7- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3H-imidazo [4, 5-b ] pyridin-3-yl ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide (Compound I)

To a 3-neck 250ml round bottom flask equipped with a mechanical stirrer, thermocouple, nitrogen inlet and condenser, were added sequentially at 22 ℃: 8.4g of compound IX in the form of the dihydrochloride monohydrate, 54.3g of n-butyl acetate and 4.5g of formamidine acetate. The suspension is stirred while being heated to 90 ℃ for 2 to 4 hours. After completion of the reaction (disappearance of compound IX) the reaction mixture was cooled to 60 ℃ and washed with a warm dilute solution of sodium bicarbonate and then with 45g of warm water. After removal of the aqueous layer, the organic solution was treated with 400mg of activated carbon and 0.5g of water and heated to 70 ℃ for 45 minutes with stirring. The hot suspension was filtered and the filtrate was cooled to room temperature and stirred at 22 ℃ for a further 2 hours. The resulting solid was collected by filtration, washed with butyl acetate and dried in a vacuum oven at 50 ℃.

Those skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The compounds and methods described herein are representative of preferred embodiments or are illustrative and are not intended to limit the scope of the invention.

Claims (10)

1. A process for the preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide comprising reducing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ - [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethylamino ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethylin the presence of platinum and ammonium formate on a water-wetting carbon Tetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide.

2. A process for the preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide which comprises reducing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2 in the presence of zinc and ammonium acetate, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide.

3. A process for the preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide which comprises reducing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro- 2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide.

4. A process for the preparation of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide which comprises trans-reacting (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine and 2R, 3S-isopropylidenedioxy-4R-amino-1S-ethylaminocarbonylcyclopentane in the presence of an alkali metal carbonate Should be used.

5. A process for the preparation of (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine which comprises replacing the hydroxyl moiety in (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine.

6. A process for the preparation of (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine comprising reacting 4-chloro-3-nitropyridin-2 (1H) -one with (R) -3-chloro-a-ethyl-2-thienylethylamine.

7. A process for the preparation of 4-hydroxy-3-nitro-2 (1H) -pyridone comprising hydrolysis and decarboxylation of 2-hydroxy-3-cyano-4-methoxypyridine to give 2, 4-dihydroxypyridine followed by nitration of said 2, 4-dihydroxypyridine.

8. The process of claim 7, wherein said hydrolysis, decarboxylation, and nitration are performed in a concatenated manner without intermediate isolation and purification of said 2, 4-dihydroxypyridine.

9. A process for the preparation of [1S- [1a, 2b, 3b, 4a (S) ] ] -4- [ [ 3-amino-4- [ [1- (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyl-2, 3-dihydroxycyclopentanecarboxamide dihydrochloride salt, which comprises reacting 4-chloro-3-nitropyridin-2 (1H) -one with (R) -3-chloro-a-ethyl-2-thienylethylamine to form (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine, then replacing the hydroxy moiety of (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridinamine with a chloro group to form (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridinamine, and then reacting (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridinamine with 2R, 3S-isopropylidenedioxy-4R-amino-1S-ethylaminocarbonylcyclopentane, forming [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino group, and then reducing [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino group to form [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] - N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide followed by hydrolysis of [3aR- [3aa, 4a, 6a (R), 6aa ] ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide in the presence of hydrochloric acid, said step being carried out in a catenated manner without the intermediate compound [3aR- [3aa, 4a, 6a (R) ], 6aa ] -6- [ [ 3-amino-4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, 3-dioxole-4-carboxamide, [3aR- [3aa, 4a, 6a (R), 6aa ] -6- [ [4- [ [1- [ (3-chloro-2-thienyl) methyl ] propyl ] amino ] -3-nitro-2-pyridyl ] amino ] -N-ethyltetrahydro-2, 2-dimethyl-4H-cyclopenta-1, intermediate isolation and purification of 3-dioxole-4-carboxamide, (R) -2-chloro-N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -3-nitro-4-pyridylamine or (R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridylamine.

(R) -N- [1- [ (3-chloro-2-thienyl) methyl ] propyl ] -2-hydroxy-3-nitro-4-pyridineamine.