CN105367572A

CN105367572A - Intermediate for preparing compound as dipeptidyl peptidase-4 inhibitor

Info

Publication number: CN105367572A
Application number: CN201510889559.9A
Authority: CN
Inventors: 王莺妹; 何人宝
Original assignee: ZHEJIANG YONGTAI TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG YONGTAI TECHNOLOGY Co Ltd
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2016-03-02
Anticipated expiration: 2034-12-26
Also published as: CN104592235B; CN104592235A; CN105367572B

Abstract

The present invention relates to an intermediate for preparing a compound as a dipeptidyl peptidase-4 inhibitor. The biguanide derivative can be used for the treatment of all conditions or disorders benefiting from inhibition of DPP-IV activity, such as type I and type II diabetes, diabetic complications and other related diseases.

Description

Intermediate for preparing compound as dipeptidyl peptidase-4 inhibitor

The invention relates to a split application of an invention patent application with application number 201410830416.6, wherein the application date of the original application is 26 days 12 months 2014, the application number is 201410830416.6, the publication date is 06 months 05 months 2015, and the name of the invention is 'an intermediate for preparing a compound serving as a dipeptidyl peptidase-4 inhibitor'.

Technical Field

The present invention relates to an intermediate compound for the preparation of biguanide derivatives as dipeptidyl peptidase-4 inhibitors, which are useful in the treatment of all symptoms or conditions that would benefit from the inhibition of DPP-IV activity, such as type I and type II diabetes, diabetic complications, and the like.

Background

Dipeptidyl peptidase-4 (DPP-4) is a highly specific serine protease whose natural substrates are glucagon-like peptide 1(GLP-1) and the glucagons polypeptide (GIP). GLP-1 has multiple physiological functions, and can increase glucose-dependent insulin secretion in pancreas, inhibit glucagon secretion, and promote islet D cell proliferation; in the gastrointestinal tract, the gastric emptying can be delayed after meal, thereby delaying the glucose absorption of the intestinal tract. GIP has an insulinotropic function. DPP-4 can rapidly degrade GLP-l and GIP in vivo to inactivate them. GLP-1 in a healthy human body is mainly secreted by L cells of ileum and colon, the basic concentration in the human body is about 5-10 pmol/L, and the postprandial concentration can be increased by 2-3 times. Its biologically active half-life is only about 2 minutes. The DPP-4 inhibitor reduces the catalytic activity of the enzyme by competitively binding with the DPP-4 activation site, thereby inhibiting the degradation of GLP-1 and GIP.

DPP-4 is widely found in vivo tissues such as plasma, gastrointestinal tract, kidney, lymph node and connective tissue, with the largest number of kidneys. The family members include DPP-1, DPP-2, DPP-3, DPP-4, DPP-8, DPP-9 and fibroblast activation protein-alpha (FAP). The molecular weight of DPP-4 is 220kD, the active body is in a dimer form, each subunit comprises two structural domains, the inlet and outlet of a control substrate are positioned in a large cavity with the size of 30-45A between the two structural domains, the bag-shaped structure in the cavity is the active site of DPP-4, and all polypeptides with proline (Pro) or alanine (Ala) at the second position of the N end of the structure are main substrates for the DPP-4 to exert activity.

Due to the rapid degradation of DPP-4 in vivo, GLP-1 has a very short half-life (<2min) in vivo, and researches show that the action time of GLP-1 is effectively prolonged after DPP-4 activity is inhibited, so that the effect of reducing blood sugar level is achieved. The DPP-4 inhibitor has an action mechanism based on that the structure is similar to that of a natural substrate, the DPP-4 inhibitor contains an Xaa-Pro similar structure, can be competitively combined with the DPP-4 active site, and has far higher affinity than the natural substrate, so that the conformation of DPP-4 is changed, and the catalytic activity is reduced. Experiments prove that the DPP-4 inhibitor can reversibly inhibit DPP-4 enzyme activity by about 90 percent within 24 h. Therefore, the DPP-4 inhibitor can prolong the time of the hypoglycemic action by increasing the concentration of GLP-1 in vivo, inhibit the secretion of glucagon and prolong the stimulation duration of GLP-1 to the secretion of insulin. Since the regulatory effect of GLP-1 on insulin secretion exhibits strict blood glucose concentration dependence, GLP-1 increases insulin secretion only at elevated blood glucose levels, DPP-4 inhibitors do not pose a risk of hypoglycemia. The DPP-4 inhibitor has unique action mechanism and good safety characteristic, and becomes a hot field for researching new drugs for diabetes. It has been found that the combined treatment of diabetes with some DPP-4 inhibitors and metformin can significantly improve blood glucose levels with a lower risk of hypoglycemia, weight gain and other adverse events. But still lack the single compounds with low incidence of hypoglycemia, weight gain, and other adverse event risks.

Disclosure of Invention

The invention provides a class of intermediate compounds of biguanide derivatives as DPP-IV inhibitors, which can be used for preventing or treating related diseases benefiting from DPP-IV inhibition, and has low incidence rate of hypoglycemia, weight gain and other adverse events. Specifically, the present invention provides a compound represented by the following formula (II), a stereoisomer thereof, or a salt thereof:

wherein,

R¹represents C_1-8Alkyl radical, said C_1-8Alkyl can be substituted by R¹¹Or R¹²-CO-substituted, and R¹¹Represents C_6-10Aryl, quinolyl, isoquinolyl, quinazolinyl, cinnolinyl or indolyl, R¹²Represents di (C)_1-6Alkyl) amino, pyrrolidin-1-yl, piperidin-1-yl or C_6-10An aryl group;

R²represents C_1-8Alkyl or C_6-10An aryl group;

R³represents benzyl, C_2-8Alkenyl radical, C_2-8Alkynyl or C_3-8Cycloalkenylmethyl, wherein the phenyl ring in benzyl can be substituted with 1 or more halogens or cyano groups;

R⁴represents C_1-8Alkyl radical, C_3-8Cycloalkyl radical, C_3-8Membered heterocycloalkyl, C_6-10Aryl or C_5-10A membered heteroaryl group;

R⁵represents hydrogen or represents an amino protecting group.

Wherein said amino protecting group is well known in the art and includes, but is not limited to, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 2-biphenyl-2-propoxycarbonyl (BPoc), p-toluenesulfonyl (Tosyl), trifluoroacetyl, fluorenylmethoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilyloxycarbonyl (Teoc), phthaloyl (Pht), p-toluenesulfonyl (Tos), trifluoroacetyl (Tfa), o-or p-nitrobenzenesulfonyl (Ns), pivaloyl, benzoyl, trityl (Trt), 2, 4-dimethoxybenzyl (Dmb), p-methoxybenzyl (PMB), benzyl, and the like.

In a preferred embodiment, R¹Represents dimethylaminocarbonylmethyl, pyrrolidin-1-ylcarbonylmethyl, phenylcarbonylmethyl, benzyl, quinolinylmethyl, isoquinolinylmethyl, quinazolinylmethyl or cinnolinylmethyl.

In another preferred embodiment, R²Represents methyl, isopropyl or phenyl.

In another preferred embodiment, R³Represents 2-methyl-2-propen-1-yl, 2-buten-1-yl, 2, 3-dimethyl-2-buten-1-yl, 2-butyn-1-yl, 1-cyclopenten-1-ylmethyl, 1-cyclohexen-1-ylmethylBenzyl, 2-cyanobenzyl, 2, 6-dicyanobenzyl.

In another preferred embodiment, R⁴Represents n-butyl, cyclohexyl, phenyl, piperidinyl or pyridinyl.

Salts of the compounds of the present invention include all acid addition salts and all salts formed with bases. In particular, the salts include water-insoluble salts as well as water-soluble salts. Inorganic acids suitable for the acid addition salts of the present invention include, but are not limited to, hydrochloric, hydrobromic, phosphoric, sulfuric, and the like. Organic acids suitable for the acid addition salts of the present invention include, for example and without limitation, citric acid, maleic acid, fumaric acid, succinic acid, lactic acid, tartaric acid, methanesulfonic acid, and the like. Preferably, the salt of the compound of the present invention may be a salt for isolation or purification of the free compound of the compound of formula (II) or a stereoisomer thereof, or a salt thereof. Thus, salts with inorganic or organic acids can include, but are not limited to, hydrochloride, hydrobromide, phosphate, sulfate, citrate, maleate, fumarate, succinate, lactate, tartrate, methanesulfonate, mandelate and the like.

Unless a particular isomeric form is specifically indicated, all isomeric forms of the compounds of formula (II) are intended to be within the present invention, including all regioisomeric and stereoisomeric forms, e.g. all chiral, enantiomeric, diastereomeric, racemic, tautomeric forms and all geometric isomeric forms. Clearly, the most pharmaceutically effective isomer with the least adverse side effects is preferred.

It is to be understood that the compounds of the present invention contain at least one, two or more asymmetrically substituted carbon atoms, and may be isolated in optically active or racemic forms as pure diastereomers or diastereomeric mixtures.

The present invention encompasses all possible stereoisomers, in particular diastereomers and enantiomers mentioned herein, for example in substantially pure form, in enriched form and/or in any mixing ratio, including racemic forms, and salts thereof.

In general, substantially pure stereoisomers can be obtained according to synthetic principles well known to the person skilled in the art, for example by separation of the corresponding mixtures, by using stereochemically pure starting materials and/or by stereoselective synthesis. It is known in the art how to prepare optically active forms, such as by resolution of racemic forms or by synthesis, for example from optically active starting materials and/or by using chiral reagents.

Enantiomerically pure compounds of the invention may be prepared by asymmetric synthesis, for example by preparation and isolation of the appropriate diastereomeric compound/intermediate, which may be isolated by known separation, for example chiral chromatographic separation or fractional crystallization from a suitable solvent, and/or by use of chiral reaction components (e.g. chiral reagents, chiral catalysts, chiral ligands, chiral synthons, chiral building blocks, etc.).

Furthermore, the person skilled in the art knows how to prepare enantiomerically pure compounds from the corresponding racemic mixtures, for example by chromatographic separation of the corresponding racemic compounds on a chiral separation column; or by resolving racemic compounds using a suitable resolving agent; for example by forming diastereomeric salts of racemic compounds with optically active acids or bases, followed by resolution of the salt and liberation of the desired compound from the salt; or by derivatizing the corresponding racemic compound using a chiral auxiliary, followed by separation of the diastereomers and removal of the chiral auxiliary group; by kinetic resolution of the racemate (e.g., by enzymatic resolution); enantioselective crystallization from an aggregate of mirror image crystals under suitable conditions; or by fractional crystallization from a suitable solvent in the presence of a chiral auxiliary.

The resulting compounds of formula (II) may be separated into their enantiomers and/or diastereomers. For example, cis/trans mixtures can be separated into their cis or trans isomers, and compounds having at least one optically active carbon atom can be resolved into their enantiomers.

The enantiomers are preferably separated by the following method: column separation on a chiral phase, or recrystallization from optically active solvents, or reaction with optically active substances, especially acids and their activated derivatives or alcohols, to form salts or derivatives such as esters or amides, and separation of the diastereoisomeric mixtures of the salts or derivatives thus obtained, for example on the basis of differences in their solubility; while the free enantiomer may be released from the pure diastereoisomeric salt or derivative by the action of suitable reagents. Commonly used optically active acids are, for example, D and L tartaric acid or dibenzoyltartaric acid, di-o-tolyltartaric acid, malic acid, mandelic acid, camphorsulfonic acid, glutamic acid, aspartic acid or quinic acid. The optically active alcohol can be, for example, an optically active acyl group in (+) or (-) menthol and amides, e.g., (+) or (-) menthyloxycarbonyl.

It will be understood by those skilled in the art that the organic compounds or their salts may form complexes with the solvent with which the solvent molecules are isolated or with which they may come into contact, the solvent in which they are reacted, the solvent from which they are isolated (e.g., precipitation, crystallization, lyophilization, and the like), and the like. Some compounds of the invention may contain variable or fixed amounts of solvent (including aqueous and/or non-aqueous solvents), for example when obtained or isolated in solid form, as recognized by those skilled in the art. Accordingly, solvates of the compounds of the invention (including hydrates, organic solvates and mixed hydrates/organic solvates) are included within the scope of the invention. Solvates of the compounds of the invention may include stoichiometric or non-stoichiometric solvates, tightly bound solvates or weakly bound solvates, as well as homo-or hetero-solvates. Preferably, the solvent used is a pharmaceutically acceptable solvent, such as water and/or a low molecular weight aliphatic alcohol such as ethanol and the like. In one embodiment, solvates of the compounds of the invention may include, for example, hydrates or alcoholates, or mixed hydrates/alcoholates. The present invention includes unsolvated forms as well as all solvated forms. Likewise, the present invention includes any solvate, non-solvate, hydrate, anhydrate, hygroscopic and/or non-hygroscopic form.

The compounds of formula (II) of the present invention are useful in the preparation of compounds of formula (I) which are useful in the treatment of all conditions or disorders that would benefit from inhibition of DPP-IV activity, such as type I and type II diabetes, diabetic complications, and the like. It is therefore another object of the present invention to provide the use of a compound of formula (II) for the preparation of a DPP-IV inhibitor, and a process for the preparation of a DPP-IV inhibitor, said process comprising contacting a compound of formula (II) with dicyandiamide to obtain formula (I):

when R is⁵When representing the amino protecting group, the method also comprises the step of removing the amino protecting group before contacting with dicyandiamide.

Since the compounds of formula (I), its stereoisomers and salts thereof according to the present invention have the ability to inhibit DPP-IV activity and to modulate blood glucose levels, they are suitable for the treatment of all symptoms or conditions which could benefit from the inhibition of DPP-IV activity. Thus, it is expected that the compounds according to the invention will be suitable for the prevention or treatment of diseases or conditions such as type I and type II diabetes, diabetic complications (such as retinopathy, nephropathy or neuropathy), metabolic acidosis or ketosis, reactive hypoglycemia, insulin resistance, metabolic syndrome, lipodystrophy of different origins, arthritis, atherosclerosis and related diseases, obesity, allograft transplantation and osteoporosis caused by calcitonin. Furthermore, these substances are also suitable for preventing degeneration of beta-cells, such as apoptosis or necrosis of pancreatic beta-cells. The substance is also suitable for improving or restoring pancreatic cell function, as well as increasing the number and size of limb beta-cells. Furthermore, and based on the effect of glucagon peptides such as GLP-1 and GLP-2 and their linkage to DPP-IV inhibition, as such, the compounds according to the invention are useful for achieving additional sedative or anxiolytic effects and also favorably influencing the catabolic state after surgery or hormonal stress response, or reducing mortality or morbidity after myocardial infarction. It is also suitable for the treatment of all the symptoms associated with the above mentioned effects and introduced by GLP-1 or GLP-2. The compounds according to the invention can also be used as diuretics or antihypertensive agents and are suitable for the prophylaxis and treatment of acute renal failure. Furthermore, the compounds according to the invention are useful for the treatment of inflammatory diseases of the respiratory tract. It is likewise suitable for the prophylaxis and treatment of chronic inflammatory bowel diseases, such as Irritable Bowel Syndrome (IBS), Crohn's disease or ulcerative colitis, and pancreatitis. Likewise, it can be used for all kinds of injuries or lesions of the gastrointestinal tract, such as colitis and enteritis. It is also contemplated that DPP-IV inhibitors and thus the compounds according to the invention, may also be useful for treating infertility or improving fertility in humans or mammals, especially when infertility is associated with insulin resistance or polycystic ovary syndrome. On the other hand, these substances are suitable for influencing the motility of spermatozoa and can therefore be used as male contraceptives. In addition the substance is also suitable for treating growth hormone deficiency associated with dwarfism and is also advantageously used for any condition in which growth hormone is available. The compounds according to the invention are also suitable for the treatment of various autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, thyroidism and Barceland's disease, on the basis of their inhibitory effect on DPP-IV. They are also useful in the treatment of viral diseases and, for example, in HIV infection, in stimulating blood production, in benign prostatic hyperplasia, gingivitis, and in the treatment of neuronal defects and neurodegenerative diseases such as Alzheimer's disease. The compounds are also useful in the treatment of obese tumors, particularly in altering tumor invasion and metastasis; examples here are their use in the treatment of T-cell lymphoma, acute lymphocytic lymphoma leukemia, cell-based thyroid cancer, basal cell carcinoma or breast cancer. Other indications are stroke, myocardial ischemia of various origins, parkinson's disease and migraine. In addition, other indications include folliculitis and epidermal hyperkeratosis, increased keratinocyte proliferation, psoriasis, cerebrospinal inflammation, glomerulonephritis, lipodystrophy and psychosomatic, depressive and neuropsychiatric diseases of all different origins.

The compounds of formula (I) or a pharmaceutically acceptable salt thereof according to the invention can be used as medicaments, for example in the form of pharmaceutical compositions for enteral, parenteral or topical administration. They may be administered in any of the generally accepted modes of administration available in the art, for example orally, for example in the form of tablets, coated tablets, sugar-coated tablets, hard and soft gelatin capsules, solutions, emulsions or suspensions, rectally, for example in the form of suppositories, parenterally (including intravenously), for example in the form of injection or infusion solutions, or topically, for example in the form of ointments, creams or oils. Among the possible modes of administration, oral and intravenous delivery are preferred.

The pharmaceutical compositions of the invention may generally contain a total amount of from about 0.05 to 80% by weight or from about 0.1 to 50% by weight of at least one compound of formula (I) of the invention, optionally together with pharmaceutically acceptable carriers and/or excipients.

The amount of a compound of formula (I) of the invention, or a tautomer or salt thereof, included in a dosage form or pharmaceutical composition of the invention, in addition to one or more excipients, may be at least 0.1% to 0.5%, or at least 0.5% to 1.5%, or at least 1% to 3%.

The person skilled in the art is familiar, based on his/her expert knowledge, with pharmaceutically acceptable excipients, such as diluents, carriers, binders, disintegrants, surfactants, lubricants, carriers, auxiliaries, adjuvants and/or, other additives known to be suitable for the preparation of pharmaceutical compositions.

As pharmaceutically acceptable excipients, any excipient generally known to be suitable for pharmaceutical compositions is contemplated. Examples include, but are not limited to, diluents, fillers, binders, disintegrants, lubricants, glidants, solvents, dispersants, emulsifiers, solubilizers, gel formers, ointment bases, antioxidants, preservatives, stabilizers, carriers, thickeners, complexing agents, buffers, pH adjusters (e.g., to obtain a neutral, basic or acidic formulation), permeation enhancers, polymers, coating agents, propellants, tonicity adjusters, surfactants, colorants, flavors, sweeteners, and dyes.

In general, suitable support materials are not only inorganic support materials but also organic support materials. Thus, for example, lactose, starch (e.g. corn starch) or derivatives thereof, talc, silicon dioxide, polyvinylpyrrolidone, stearic acid or salts thereof can be used as carrier materials for tablets, coated tablets, dragees and hard gelatine capsules. Suitable carrier materials for soft gelatine capsules are, for example, vegetable oils, waxes, fats and semi-solid and liquid polyols. Suitable carrier materials for the production of solutions and syrups are, for example, water, polyols, sucrose, invert sugar and the like. Suitable carrier materials for injection or infusion solutions are, for example, water, alcohols, polyols, glycerol and vegetable oils. Suitable carrier materials for suppositories are, for example, neutral or hardened oils, waxes, fats and semi-liquid or liquid polyols or polyethylene glycols. Suitable carrier materials for topical formulations are glycerides, semi-synthetic and synthetic glycerides, hydrogenated oils, liquid waxes, liquid paraffins, liquid fatty alcohols, sterols, polyethylene glycols and cellulose derivatives.

Excipients, carriers and/or diluents of the type appropriate to the desired pharmaceutical composition, formulation or preparation and the desired mode of administration are employed.

The pharmaceutical compositions of the present invention may be obtained by mixing one or more compounds of formula (I) or a pharmaceutically acceptable salt thereof with suitable excipients such as known inert diluents, carriers, disintegrants, adjuvants, surfactants, binders and/or lubricants. The tablet may also be composed of several layers. The compositions of the present invention may also contain other active substances.

The compositions of the invention may thus be prepared by processes known per se and familiar to the person skilled in the art, for example by incorporating a compound of the formula (I) or a pharmaceutically acceptable salt thereof, optionally together with one or more conventional solid or liquid carriers and/or diluents, into conventional formulations such as conventional or coated tablets, capsules, powders, suspensions or suppositories. Examples of such carriers include, but are not limited to, corn starch, lactose, glucose, microcrystalline cellulose, magnesium stearate, polyvinylpyrrolidone, citric acid, tartaric acid, water/ethanol, water/glycerol, water/sorbitol, water/polyethylene glycol, cetearyl alcohol, carboxymethyl cellulose or fatty substances such as hard fat or suitable mixtures thereof.

Examples of suitable diluents for the compounds of the invention may include cellulose powder, dibasic calcium phosphate, erythritol, low substituted hydroxypropyl cellulose, mannitol, pregelatinized starch or xylitol.

The dosage of the compounds of the invention may vary within wide limits depending on the compound to be administered, the nature and severity of the disease to be treated or prevented, the age and the individual condition of the patient and the mode and frequency of administration, and will of course correspond to the individual requirements in each particular case. In general, the amount of the compounds of the invention is of the order of magnitude commonly used for DPP-IV inhibitors. When administered by intravenous route, the compounds of the invention may generally be required in a dose of from 0.001mg to 10mg, or from 0.01mg to 10mg, or from 0.1mg to 10mg, such as from 0.25mg to 5mg, and when administered by oral route, from 0.005mg to 100mg, or from 0.05mg to 100mg, or from 0.5mg to 100mg, such as from 2.5mg to 50mg or from 0.5mg to 10mg, preferably from 2.5mg to 10mg or from 1mg to 5mg, in each case from 1 to 4 times a day. Depending on the dose, it may be convenient to administer the daily dose in several dosage units.

General preparation method

The compounds of the invention can be obtained using the following general preparative procedures which comprise:

contacting a compound of formula (III) with a compound of formula (IV), followed by removal of the protecting group to obtain a compound of formula (II):

wherein R in the formula (II)⁵When representing hydrogen, the amino protecting group Pr is optionally substituted¹And (4) removing.

Wherein the compound of formula (IV) can be prepared by sequentially passing 3-aminopiperidine (compound of formula (V)) through different amino protecting groups Pr¹、Pr²Protection, then introduction of R⁴Radical, re-selective Pr removal²Protecting groups to produce:

the compounds of formula (III) may be prepared from 8-halogenated xanthine derivatives which in turn may be substituted by R¹Halides of radicals and R³Halo substitution of the group to yield:

wherein X represents a halogen atom and Pr represents an amino-protecting group. Amino protecting groups are those well known in the art and include, but are not limited to, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 2-biphenyl-2-propoxycarbonyl (BPoc), p-toluenesulfonyl (Tosyl), trifluoroacetyl, fluorenyl methoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilyloxycarbonyl (Teoc), phthaloyl (Pht), p-toluenesulfonyl (Tos), trifluoroacetyl (Tfa), o-or p-nitrobenzenesulfonyl (Ns), pivaloyl, benzoyl, trityl (Trt), 2, 4-dimethoxybenzyl (Dmb), p-methoxybenzyl (PMB), benzyl, and the like.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Preparation of the Compound of formula (III)

Preparation of 8-bromo-7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (compound III-1)

(1)Preparation of 3-methyl-7- (2-butyn-1-yl) -8-bromo-3, 7-xanthine

3-methyl-8-bromo-xanthine was mixed with N, N-dimethylformamide solution of N-ethyldiisopropylamine (DIPEA), 1-bromo-2-butyne was added, and stirred at room temperature overnight. For work-up, the reaction mixture was poured into water. Filtering the precipitate, washing with water, and drying to obtain 3-methyl-7- (2-butyn-1-yl) -8-bromo-xanthine (molecular formula: C)₁₀H₉BrN₄O₂)。

Mass spectrometry (ESI)⁺)：m/z＝298[M+H]⁺

Elemental analysis: c, 40.43; h, 3.05; br, 26.89; n, 18.86; o,10.77

(2)Preparation of 8-bromo-7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine

2- (2-bromoethyl) -4-methyl quinazoline was added to a mixed solution of 3-methyl-7- (2-butyn-1-yl) -8-chloro-xanthine and potassium carbonate in N, N-dimethylformamide. The reaction mixture was stirred at room temperature for 8 hours. After treatment with the aqueous solution, the crude product was purified by silica gel column chromatography eluting with methylene chloride/methanol to give 8-bromo-7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (molecular formula: C)₂₀H₁₇BrN₆O₂)。

Mass spectrometry (ESI)⁺)：m/z＝454[M+H]⁺

Elemental analysis: c, 52.99; h, 3.78; br, 17.63; n, 18.54; o,7.06

¹H-NMR(d6-DMSO)：8.12(1H),7.84(1H),7.82(1H),7.58(1H),4.42(4H),3.41(3H),2.94(3H),1.80(3H)。

Preparation of 8-bromo-7- (2-cyanobenzyl) -3-methyl-1- (quinolin-2-ylmethyl) -3, 7-xanthine (compound III-2)

(1)Preparation of 8-bromo-7- (2-cyanobenzyl) -1, 3-dimethyl-3, 7-xanthine

3-methyl-8-bromo-xanthine was mixed with N, N-dimethylformamide solution of N-ethyldiisopropylamine (DIPEA), 2-cyanobenzylbromide was added, and stirred at room temperature overnight. For work-up, the reaction mixture was poured into water. Filtering the precipitate, washing with water, and drying to obtain 3-methyl-7- (2-cyanobenzyl) -8-bromo-xanthine (molecular formula: C)₁₄H₁₀BrN₅O₂)。

Mass spectrometry (ESI)⁺)：m/z＝36[1M+H]⁺；

Elemental analysis: c, 46.69; h, 2.80; br, 22.19; n, 19.44; and O, 8.88.

(2)Preparation of 8-bromo-7- (2-cyanobenzyl) -3-methyl-1- (quinolin-2-ylmethyl) -3, 7-xanthine

2- (2-bromoethyl) -quinoline was added to a mixed solution of 3-methyl-7- (2-cyanobenzyl) -8-chloro-xanthine and potassium carbonate in N, N-dimethylformamide. The reaction mixture was stirred at room temperature for 8 hours. After treatment with the aqueous solution, the crude product was purified by silica gel column chromatography eluting with methylene chloride/methanol to give 1- (quinolin-2-ylmethyl) -3-methyl-7- (2-cyanobenzyl) -8-bromo-3, 7-xanthine (formula: C)₂₄H₁₇BrN₆O₂)。

Mass spectrometry (ESI)⁺)：m/z＝502[M+H]⁺；

Elemental analysis: c, 57.50; h, 3.42; br, 15.94; n, 16.76; and O, 6.38.

¹H-NMR(d6-DMSO)：8.07(1H),8.01(1H),7.79(1H),7.64(1H),7.48-7.55(4H),7.32(2H),5.47(2H),4.76(2H),3.40(3H)

Preparation of 8-bromo-7- (1-cyclohexenylmethyl) -3-methyl-1- (dimethylaminocarbonylmethyl) -3, 7-xanthine (Compound III-3)

(1)Preparation of 3-methyl-7- (1-cyclohexenylmethyl) -8-bromo-xanthine

3-methyl-8-bromo-xanthine was mixed with N, N-dimethylformamide solution of N-ethyldiisopropylamine (DIPEA), 1-cyclohexenylmethylbromide was added and stirred at room temperature overnight. For work-up, the reaction mixture was poured into water. Filtering the precipitate, washing with water, and drying to obtain 3-methyl-7- (1-cyclohexenylmethyl) -8-bromo-xanthine (molecular formula: C)₁₃H₁₅BrN₄O₂)。

Mass spectrometry (ESI)⁺)：m/z＝340[M+H]⁺；

Elemental analysis: c, 46.03; h, 4.46; br, 23.56; n, 16.52; and O, 9.43.

(2)Preparation of 8-bromo-7- (1-cyclohexenylmethyl) -3-methyl-1- (dimethylaminocarbonylmethyl) -3, 7-xanthine

N, N-dimethyl-2-bromoacetamide was added to a mixed solution of 3-methyl-7- (1-cyclohexenylmethyl) -8-chloro-xanthine and potassium carbonate in N, N-dimethylformamide. The reaction mixture was stirred at room temperature for 8 hours. Treating with water solution, purifying the crude product by silica gel column chromatography, eluting with dichloromethane/methanol to obtain 1- (dimethylaminocarbonylmethyl) -3-methyl-7- (1-cyclohexenylmethyl) -8-bromo-3, 7-xanthine (molecular formula: C)₁₇H₂₂BrN₅O₃)。

Mass spectrometry (ESI)⁺)：m/z＝425[M+H]⁺；

Elemental analysis: c, 48.12; h, 5.23; br, 18.83; n, 16.51; o, 11.31.

¹H-NMR(d6-DMSO)：5.40(1H),4.41(2H),4.29(2H),3.42(3H),2.99(6H),1.95-1.99(4H),1.75(2H),1.61(2H)。

Preparation of 1- (pyrrolidin-1-ylcarbonylmethyl) -3-methyl-7- (2-butyn-1-yl) -8-bromo-3, 7-xanthine (compound III-4)

1- (2-Bromoacetyl) pyrrolidine was added to a mixed solution of 3-methyl-7- (2-butyn-1-yl) -8-chloro-xanthine and potassium carbonate in N, N-dimethylformamide. The reaction mixture was stirred at room temperature for 6 hours. After treatment with the aqueous solution, the crude product was purified by silica gel column chromatography eluting with methylene chloride/methanol to give 1- (pyrrolidin-1-ylcarbonylmethyl) -3-methyl-7- (2-butyn-1-yl) -8-bromo-3, 7-xanthine (formula: C)₁₆H₁₈BrN₅O₃)。

Mass spectrometry (ESI)⁺)：m/z＝409[M+H]⁺；

Elemental analysis: c, 47.07; h, 4.44; br, 19.57; n, 17.15; and O, 11.76.

¹H-NMR(d6-DMSO)：4.42(2H),4.29(2H),3.42(3H),3.10(4H),1.84(4H),1.80(3H)。

Preparation of 8-bromo-7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (compound III-5)

(1)Preparation of 3-methyl-7- (2, 3-methyl-2-buten-1-yl) -8-bromo-3, 7-xanthine

3-methyl-8-bromo-xanthine was mixed with N, N-dimethylformamide solution of N-ethyldiisopropylamine (DIPEA), 1-bromo-2, 3-methyl-2-butene was added, and stirred at room temperature overnight. Pouring the reaction mixture into water, filtering to obtain precipitate, washing with water, and drying to obtain 3-methyl-7- (2, 3-methyl-2-butene-1-yl) -8-bromo-xanthine (molecular formula: C)₁₂H₁₅BrN₄O₂)。

Mass spectrometry (ESI)⁺)：m/z＝328[M+H]⁺；

Elemental analysis: c, 44.05; h, 4.62; br, 24.42; n, 17.12; and O, 9.78.

(2)Preparation of 8-bromo-7- (2, 3-methyl-2-buten-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine Prepare for

2- (2-bromoethyl) -4-methyl quinazoline was added to a mixed solution of 3-methyl-7- (2, 3-methyl-2-buten-1-yl) -8-chloro-xanthine and potassium carbonate in N, N-dimethylformamide. The reaction mixture was stirred at room temperature for 8 hours. After treatment with the aqueous solution, the crude product was purified by silica gel column chromatography eluting with methylene chloride/methanol to give 8-bromo-7- (2, 3-methyl-2-buten-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (formula: C)₂₂H₂₃BrN₆O₂)。

Mass spectrometry (ESI)⁺)：m/z＝484[M+H]⁺；

Elemental analysis: c, 54.67; h, 4.80; br, 16.53; n, 17.39; and O, 6.62.

¹H-NMR(d6-DMSO)：8.14(1H),7.85(1H),7.82(1H),7.57(1H),4.43(2H),4.39(2H),3.42(3H),2.95(3H),1.78(9H)。

Preparation of the Compound of formula (IV)

Preparation of N-N-butyl-N- ((R) -piperidin-3-yl) carbamic acid tert-butyl ester (Compound IV-1)

(1) Preparation of benzyl (R) -3- (tert-butoxycarbonylamino) piperidine-1-carboxylate

A THF solution of (R) -3- (tert-butoxycarbonylamino) piperidine was treated with triethylamine followed by benzyl chloroformate at 0-5 deg.C and stirred at this temperature for 24 hours. The reaction mixture was then evaporated in vacuo to about 1/4 volumes and partitioned between ethyl acetate and 1M hydrochloric acid solution. The organic phase is separated off and, in order, another portion of 1M hydrochloric acid solution, saturated NaHCO is used₃Aqueous and brine solutions. The organic phase was then partially dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo to give benzyl (R) -3- (tert-butoxycarbonylamino) piperidine-1-carboxylate (formula: C)₁₈H₂₆N₂O₄)。

Mass spectrometry (ESI)⁺)：m/z＝335[M+H]⁺；

Elemental analysis: c, 64.65; h, 7.84; n, 8.38; and O, 19.14.

(2) Preparation of benzyl (R) -3- (tert-butyloxycarbonyl (n-butyl) amino) piperidine-1-carboxylate

(R) -benzyl 3- (tert-butoxycarbonylamino) piperidine-1-carboxylate was dissolved in DMF at 0-5 ℃ and treated with a 60% suspension of sodium hydride. The reaction mixture was warmed to room temperature for 10min, then cooled again and bromobutane was added. After 2 hours, warm to room temperature, add an additional amount of bromobutane, and stir the reaction mixture for 16 hours. The reaction mixture was then evaporated in vacuo to-1/4 volumes and partitioned between ethyl acetate and water. The organic phase fraction was then washed with brine solution, dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo to give a residue which was chromatographed on silica gel with ethyl acetate/hexane to give N-N-butylated product (formula: C)₂₂H₃₄N₂O₄)。

Mass spectrometry (ESI)⁺)：m/z＝391[M+H]⁺；

Elemental analysis: c, 67.66; h, 8.78; n, 7.17; o, 16.39.

(3) Preparation of N-N-butyl-N- ((R) -piperidin-3-yl) carbamic acid tert-butyl ester

The N-N-butylated product was dissolved in ethanol, treated with 10% palladium on carbon and hydrogenated under 60-70psi of hydrogen for 6 hours. The crude reaction mixture was then filtered through celite, evaporated in vacuo, and redissolved in ethanol, which was filtered through a nylon syringe filter to remove residual catalyst. The mixture was evaporated to obtain the title compound (formula: C)₁₄H₂₈N₂O₂)。

Mass spectrometry (ESI)⁺)：m/z＝257[M+H]⁺；

Elemental analysis: c, 65.59; h, 11.01; n, 10.93; and O, 12.48.

¹H-NMR(d6-DMSO)：3.61(1H),3.09(1H),2.95(2H),2.85(1H),2.75(2H),2.0(1H),1.86(1H),1.61(1H),1.51(3H),1.45(1H),1.42(9H),1.30(2H),0.89(3H)。

Preparation of (R) -N-cyclohexyl-N- (piperidin-3-yl) carbamic acid tert-butyl ester (Compound IV-2)

(R) -3- (tert-Butoxycarbonylamino) piperidine-1-carboxylic acid benzyl ester was dissolved in DMF and treated with a 60% suspension of sodium hydride. The reaction mixture was warmed to room temperature for 15 minutes, then cooled again and bromocyclohexane was added. After 2 hours, warm to room temperature, add an additional amount of bromocyclohexane, and stir the reaction mixture for 16 hours. The reaction mixture was then evaporated in vacuo to-1/4 volumes and partitioned between ethyl acetate and water. The organic phase fraction was then washed with brine solution, dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo to give a residue which was siliconized with ethyl acetate/hexaneGel chromatography to obtain the N-cyclohexylated intermediate. The N-cyclohexylated intermediate was dissolved in ethanol, treated with 10% palladium on carbon, and hydrogenated under 60-70psi of hydrogen for 6 hours. The crude reaction mixture was then filtered through celite, evaporated in vacuo, and redissolved in ethanol and filtered to remove residual catalyst. The mixture was evaporated to obtain the title compound (formula: C)₁₆H₃₀N₂O₂)。

Mass spectrometry (ESI)⁺)：m/z＝283[M+H]⁺；

Elemental analysis: c, 68.04; h, 10.71; n, 9.92; o, 11.33.

¹H-NMR(d6-DMSO)：3.61(1H),3.55(1H),3.09(1H),2.85(1H),2.74(2H),2.0(1H),1.86(1H),1.72(2H),1.61(1H),1.51(2H),1.48(2H),1.45(2H),1.43(9H),1.16(4H)。

Preparation of (R) -N-phenyl-N- (piperidin-3-yl) carbamic acid tert-butyl ester (Compound IV-3)

(R) -benzyl 3- (tert-butoxycarbonylamino) piperidine-1-carboxylate was dissolved in DMF at 0-5 ℃ and treated with a 60% suspension of sodium hydride. The reaction mixture was warmed to room temperature for 30 minutes, then cooled again, and phenyl triflate was added. After 3 hours, warm to room temperature, add an additional amount of phenyl triflate, and stir the reaction mixture for 18 hours. The reaction mixture was then evaporated in vacuo to-1/4 volumes and partitioned between ethyl acetate and water. The organic phase portion was then washed with brine solution, dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo to give a residue which was chromatographed on silica gel with ethyl acetate/hexane to give the N-phenylated intermediate. The N-phenylated intermediate was dissolved in ethanol, treated with 10% palladium on carbon, and hydrogenated under 60-70psi of hydrogen for 6 hours. The crude reaction mixture was then filtered through celite, evaporated in vacuo, and redissolved in ethanol and filtered to remove residual catalystAn oxidizing agent. The mixture was evaporated to obtain the title compound (formula: C)₁₆H₂₄N₂O₂)。

Mass spectrometry (ESI)⁺)：m/z＝277[M+H]⁺；

Elemental analysis: c, 69.53; h, 8.75; n, 10.14; and O, 11.58.

¹H-NMR(d6-DMSO)：7.72(2H),7.32(2H),6.99(1H),3.60(1H),3.28(1H),3.03(1H),2.75(2H),2.03(1H),2.01(1H),1.77(1H),1.46-1.50(2H),1.42(9H)。

Preparation of tert-butyl 3- (tert-butoxycarbonyl ((3R) -piperidin-3-yl) amino) piperidine-1-carboxylate (Compound IV-4)

(R) -benzyl 3- (tert-butoxycarbonylamino) piperidine-1-carboxylate was dissolved in DMF at 0-5 ℃ and treated with a 60% suspension of sodium hydride. The reaction mixture was warmed to room temperature for 10min, then cooled again and 3-bromopiperidine-1-carboxylic acid tert-butyl ester was added. After 2 hours, warm to room temperature, add an additional amount of tert-butyl 3-bromopiperidine-1-carboxylate and stir the reaction mixture for 16 hours. The reaction mixture was then evaporated in vacuo to-1/4 volumes and partitioned between ethyl acetate and water. The organic phase portion was then washed with brine solution, dried over anhydrous magnesium sulfate, filtered, and evaporated in vacuo to give a residue.

The residue was dissolved in ethanol, treated with 10% palladium on carbon, and hydrogenated under 60-70psi of hydrogen for 6.5 hours. The crude reaction mixture was then filtered through celite, evaporated in vacuo, and redissolved in ethanol and filtered to remove residual catalyst. The mixture was evaporated and subjected to silica gel chromatography with ethyl acetate/hexane to obtain the title compound (formula: C)₂₀H₃₇N₃O₄)。

Mass spectrometry (ESI)⁺)：m/z＝384[M+H]⁺；

Elemental analysis: c, 62.63; h, 9.72; n, 10.96; o, 16.69.

¹H-NMR(d6-DMSO)：3.75(2H),3.61(1H),3.54(2H),3.49(1H),3.08(1H),2.86(1H),2.74(2H),2.12(1H),1.87(2H),1.70(2H),1.61(2H),1.49(2H),1.42(18H)。

Preparation of the Compound of formula (II)

Example 1

l- ((4-methyl-quinazolin-2-yl) methyl) -3-methyl-7- (2-butyn-1-yl) -8- ((R) -3-n-butylamino-piperidin-1-yl) -xanthine (Compound II-1)

(R) -3-tert-Butoxycarbonyl (n-butyl) aminopiperidine (compound IV-1) is added to a mixed solution of 1- ((4-methyl-quinazolin-2-yl) methyl) -3-methyl-7- (2-butyn-1-yl) -8-chloro-xanthine (compound III-1) and sodium carbonate in dimethylsulfoxide. The reaction mixture was stirred at 60 ℃ for 18 hours. For the treatment, it is mixed with water and the precipitate formed is filtered off with suction. The solid precipitate was dissolved in dichloromethane, mixed with trifluoroacetic acid and stirred at room temperature for half an hour. For workup, the reaction mixture is diluted with dichloromethane and washed with saturated potassium carbonate solution, the organic phase is dried over anhydrous sodium sulfate, evaporated to dryness and chromatographed on a silica gel column with dichloromethane/methanol (1:0 to 4:1) to give (R) -8- (3-n-butylaminopiperidin-1-yl) -7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (formula: C)₂₉H₃₆N₈O₂)。

Mass spectrometry (ESI)⁺)：m/z＝529[M+H]⁺

Elemental analysis: c, 65.89; h, 6.86; n, 21.20; o, 6.05;

¹HNMR(d6-DMSO)：8.12(1H),7.84(2H),7.59(1H),4.43(4H),3.49(1H),3.38(3H),3.33(1H),3.22-3.28(3H),2.95(3H),2.65(1H),2.53(2H),1.80(3H),1.70(1H),1.30-1.58(7H),0.89(3H)。

example 2

Preparation of l- (quinolin-2-ylmethyl) -3-methyl-7- (2-cyanobenzyl) -8- ((R) -3-n-butylamino-piperidin-1-yl) -xanthine (compound II-2)

(R) -3-tert-Butoxycarbonyl (n-butyl) aminopiperidine (compound IV-1) is added to a mixed solution of 1- ((quinolin-2-yl) methyl) -3-methyl-7- (2-cyanobenzyl) -8-chloro-xanthine (compound III-2) and sodium carbonate in dimethylsulfoxide. The reaction mixture was stirred at 60 ℃ for 18 hours. For the treatment, it is mixed with water and the precipitate formed is filtered off with suction. The solid precipitate was dissolved in dichloromethane, mixed with trifluoroacetic acid and stirred at room temperature for half an hour. For workup, the reaction mixture is diluted with dichloromethane and washed with saturated potassium carbonate solution, the organic phase is dried over anhydrous sodium sulfate, evaporated to dryness and chromatographed on a silica gel column with dichloromethane/methanol (1:0 to 4:1) to give (R) -8- (3-n-butylaminopiperidin-1-yl) -7- (2-cyanobenzyl) -3-methyl-1- ((quinolin-2-yl) methyl) -3, 7-xanthine (formula: C)₃₃H₃₆N₈O₂；)。

Mass spectrometry (ESI)⁺)：m/z＝577[M+H]⁺；

Elemental analysis: c, 68.73; h, 6.29; n, 19.43; o, 5.55;

¹H-NMR(d6-DMSO)：8.07(1H),8.02(1H),7.76(1H),7.61(1H),7.48-7.59(4H),7.32(2H),5.46(2H),4.75(2H),3.38(1H),3.35(3H),3.32(1H),3.27(3H),2.63(1H),2.53(2H),1.70(1H),1.50(1H),1.42(2H),1.35(4H),0.89(3H)。

example 3

Preparation of l- (dimethylaminocarbonylmethyl) -3-methyl-7- (cyclohexen-1-ylmethyl) -8- ((R) -3-cyclohexylamino-piperidin-1-yl) -xanthine (compound II-3)

(R) -3-tert-Butoxycarbonylaminopiperidine (cyclohexyl) aminopiperidine (compound IV-2) is added to a dimethylsulfoxide mixed solution of 1- (dimethylaminocarbonylmethyl) -3-methyl-7- (cyclohexen-1-ylmethyl) -8-chloro-xanthine (compound III-3) and sodium carbonate. The reaction mixture was stirred at 55 ℃ for 18 hours. For the treatment, it is mixed with water and the precipitate formed is filtered off with suction. The solid precipitate was dissolved in dichloromethane, mixed with trifluoroacetic acid and stirred at room temperature for half an hour. For the treatment, the reaction mixture was diluted with dichloromethane and washed with saturated potassium carbonate solution, the organic phase was dried over anhydrous sodium sulfate, evaporated to dryness and subjected to silica gel column chromatography eluting with dichloromethane/methanol (1:0 to 4:1) to give (R) -1- (dimethylaminocarbonylmethyl) -3-methyl-7- (cyclohexen-1-ylmethyl) -8- (3-n-butylaminopiperidin-1-yl) -3, 7-xanthine (formula: C)₂₈H₄₃N₇O₃；)。

Mass spectrometry (ESI)⁺)：m/z＝526[M+H]⁺；

Elemental analysis: c, 63.97; h, 8.25; n, 18.65; o, 9.13;

¹H-NMR(d6-DMSO)：5.41(1H),4.40(2H),4.28(2H),3.48(1H),3.41(3H),3.34(1H),3.27(2H),3.21(1H),2.98(6H),2.63(1H),2.55(1H),1.99(2H),1.92(2H),1.74(2H),1.71(1H),1.61(4H),1.57(1H),1.47(4H),1.35(2H),1.21(2H),1.10(2H)。

example 4

Preparation of l- (pyrrolidin-1-ylcarbonylmethyl) -3-methyl-7- (2-butyn-1-yl) -8- ((R) -3-phenylamino-piperidin-1-yl) -xanthine (compound II-4)

(R) -3-tert-Butoxycarbonylaminopiperidine (Compound IV-3) was added to a dimethylsulfoxide mixture solution of 1- (pyrrolidin-1-ylcarbonylmethyl) -3-methyl-7- (2-butyn-1-yl) -8-chloro-xanthine (Compound III-1) and sodium carbonate. The reaction mixture was stirred at 60 ℃ for 20 hours. For the treatment, it is mixed with water and the precipitate formed is filtered off with suction. The solid precipitate was dissolved in dichloromethane, mixed with trifluoroacetic acid and stirred at room temperature for half an hour. For workup, the reaction mixture is diluted with dichloromethane and washed with saturated potassium carbonate solution, the organic phase is dried over anhydrous sodium sulfate, evaporated to dryness and chromatographed on a silica gel column with dichloromethane/methanol (1:0 to 4:1) to give l- (pyrrolidin-1-ylcarbonylmethyl) -3-methyl-7- (2-butyn-1-yl) -8- ((R) -3-phenylamino-piperidin-1-yl) -xanthine (formula: C)₂₇H₃₃N₇O₂；)。

Mass spectrometry (ESI)⁺)：m/z＝504[M+H]⁺；

Elemental analysis: c, 64.39; h, 6.61; n, 19.47; o, 9.53;

¹H-NMR(d6-DMSO)：7.08(2H),6.83(2H),6.67(1H),5.15(1H),4.42(2H),4.28(2H),3.58(1H),3.42(3H),3.34(1H),3.28(2H),3.09(4H),2.63(1H),1.83(4H),1.81(1H),1.78(3H),1.55(2H),1.46(1H)。

example 5

Preparation of l- (4-quinazolin-2-ylmethyl) -3-methyl-7- (2, 3-dimethylbut-2-en-1-yl) -8- ((R) -3- (piperidin-3-ylamino) piperidin-1-yl) -xanthine (Compound II-5)

(R) -3-tert-Butoxycarbonyl (n-butyl) aminopiperidine (compound IV-1) is added to a mixed solution of 1- ((4-methyl-quinazolin-2-yl) methyl) -3-methyl-7- (2, 3-dimethylbut-2-en-1-yl) -8-chloro-xanthine (compound III-1) and sodium carbonate in dimethylsulfoxide. The reaction mixture was stirred at 55 ℃ for 20 hours. For the treatment, it is mixed with water and the precipitate formed is filtered off with suction. The solid precipitate was dissolved in dichloromethane, mixed with trifluoroacetic acid and stirred at room temperature for half an hour. For workup, the reaction mixture is diluted with dichloromethane and washed with saturated potassium carbonate solution, the organic phase is dried over anhydrous sodium sulfate, evaporated to dryness and chromatographed on a silica gel column with dichloromethane/methanol (1:0 to 4:1) to give l- (4-quinazolin-2-ylmethyl) -3-methyl-7- (2, 3-dimethylbut-2-en-1-yl) -8- ((R) -3- (piperidin-3-ylamino) piperidin-1-yl) -xanthine (formula: C)₃₂H₄₃N₉O₂；)。

Mass spectrometry (ESI)⁺)：m/z＝586[M+H]⁺；

Elemental analysis: c, 65.62; h, 7.40; n, 21.52; o, 5.46;

¹H-NMR(d6-DMSO)：8.11(1H),7.85(2H),7.59(1H),4.43(2H),4.39(2H),3.49(1H),3.39(3H),3.31(1H),3.27(2H),3.22(1H),2.94(3H),2.87(1H),2.76(2H),2.71(1H),2.63(2H),2.02(1H),1.79(9H),1.71(2H),1.58(4H),1.48(2H)。

the following compounds can also be prepared in a similar manner:

TABLE 1

The application example is as follows:preparation of the end product

1. Preparation of l- ((4-methyl-quinazolin-2-yl) methyl) -3-methyl-7- (2-butyn-1-yl) -8- ((R) -3- (N1-N-butylbiguanidino) -piperidin-1-yl) -xanthine (Compound I-1)

Dissolving dicyandiamide in isopropanol, adding (R) -8- (3-n-butylaminopiperidin-1-yl) -7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (compound II-1), adjusting the pH to 5-6 by 36% HCl, controlling the temperature to be 80-100 ℃ for 6 hours, standing and cooling after the reaction is finished, separating out a large amount of white crystals, performing suction filtration, washing, drying, and recrystallizing by absolute ethyl alcohol to obtain a title compound (molecular formula: C)₃₁H₄₀N₁₂O₂；)。

Mass spectrometry (ESI)⁺)：m/z＝613[M+H]⁺；

Elemental analysis: c, 60.77; h, 6.58; n, 27.43; o, 5.22;

¹H-NMR(d6-DMSO)：8.12(1H),7.85(2H,br),7.80(2H),7.59(1H),6.63(2H,br),4.43(4H),3.59(1H),3.38(3H),3.34(1H),3.30(2H),3.28(2H),2.95(3H),2.65(1H),2.0(1H,br),1.80(3H),1.70(1H),1.30-1.58(7H),0.89(3H)。

preparation of l- ((4-methyl-quinazolin-2-yl) methyl) -3-methyl-7- (2-cyanobenzyl) -8- ((R) -3- (N1-N-butylbiguanidino) -piperidin-1-yl) -xanthine (Compound I-2)

Dissolving dicyandiamide in isopropanol, adding (R) -8- (3-n-butylaminopiperidin-1-yl) -7- (2-butyn-1-yl) -3-methyl-1- ((4-methylquinazolin-2-yl) methyl) -3, 7-xanthine (compound II-1), adjusting the pH to 5-6 by 36% HCl, controlling the temperature to be 80-100 ℃ for 6 hours, standing and cooling after the reaction is finished, separating out a large amount of white crystals, performing suction filtration, washing, drying, and recrystallizing by absolute ethyl alcohol to obtain a title compound (molecular formula: C)₃₅H₄₀N₁₂O₂)。

Mass spectrometry (ESI)⁺)：m/z＝661[M+H]⁺

Elemental analysis: c, 63.62; h, 6.10; n, 25.44; and O, 4.84.

¹H-NMR(d6-DMSO)：8.06(1H),8.01(1H),7.83(2H),7.75(1H),7.63(1H),7.52(3H),7.46(1H),7.30(2H),6.62(2H),5.47(2H),4.76(2H),3.61(1H),3.39(3H),3.34(1H),3.30(2H),3.25(2H),2.63(1H),2.15(1H),1.83(1H),1.48-1.58(5H),1.30(2H),0.89(3H)。

The following compounds were prepared in a similar manner

TABLE 2

Biological examples

DPP-IV assay

An extract of the human colon cancer cell line Caco-2 was used as a DPP-IV source. To induce DPP-IV expression, differentiation of the cells is carried out as described in the literature (Reiher et al, "increased expression of the intestinal cell line Caco-2", Proc. Natl. Acad. Sci. Vol.90, pp.5757-5761 (1993)). The cell extracts were obtained by centrifugation at 35,000g for 30 minutes (to remove cell debris) at 4 ℃ and dissolving them in buffer (10 μm tnsc 1,0.15m nacl,0.04t.i.u. aprotinin, 0.5% Nonidet-P40, ph 8.0).

50 microliters of the amido-4-trifluoromethylcoumarin (AFC) matrix solution at a final concentration of 100 μm was placed in a black microtiter plate. Mu.l of detection buffer (final concentration 50. mu. mTns-HCl, pH7.8, 50. mu. mNaCl, 1% DMSO) were pipetted. The reaction was started by adding 30 microliters of solubilized Caco-2 protein (final concentration of 0.14 micrograms of protein per well). Usually, the test substance to be investigated is added after pre-dilution in 20. mu.l of detection buffer, wherein the volume of the detection buffer is correspondingly reduced. The reaction was carried out at room temperature and incubated for 60 minutes. Fluorescence was then measured in a Victor14Multilabel counter with an excitation wavelength of 405 nm and an emission wavelength of 535 nm. Blank readings (corresponding to 0% activity) were obtained in the mixture without any Caco-2 protein (volume from detection buffer exchange) and control values (corresponding to 100% activity) were obtained in the mixture without added substance. The potency of the test substance in question, as IC₅₀Values are represented, calculated from the dose/activity curve, which in each case contains 11 measurement points.

IC of example Compounds I-1 to 13 (biguanide derivatives) of the present invention₅₀A value of 10nM or less and IC thereof₅₀Values are significantly lower than for the corresponding amino derivatives, for example, less than about 1/5-1/10. The detailed results are shown in Table 2 below.

Table 2: inhibition of DPP-IV by Compounds of the invention

Compound numbering	IC₅₀(nM)
		Compound I-1	0.5
Compound I-2	0.3
		Compound I-3	0.06
Compound I-4	0.2
		Compound I-5	0.05
Compound I-6	0.01
		Compound I-7	0.08
Compound I-8	0.5
		Compound I-9	0.09
Compound I-10	0.3
		Compound I-11	0.2
Compound I-12	0.15
		Compound I-13	0.10

2. Effect of Compounds of the invention on blood glucose in alloxan diabetic mice

60 healthy mice are selected, 10 mice are randomly selected as a normal control group (physiological saline 0.5 ml/mouse), the rest 50 mice are fasted and are not forbidden to be watered for 24 hours, each mouse is injected with alloxan 180mg/kg in the abdominal cavity, blood glucose is measured by orbital blood sampling for 72 hours, and the mice with the blood glucose concentration higher than 11.1mmol/L are diabetes model mice. 50 diabetes model mice were randomized into 5 groups: experimental diabetes blank group (physiological saline 0.5 ml/body), linagliptin group (5mg/kg), high dose group (5mg/kg), medium dose group (1mg/kg), low dose group (0.2mg/kg) of the compound of the present invention. The administration is carried out by intragastric administration at 8: 00-9: 00 every morning for 30 days continuously. After fasting for 12h, blood is taken from the retroorbital venous plexus of the mice to measure the blood sugar value.

The results show that the compounds I-1 to 13 (biguanide derivatives) according to the examples of the present invention all exhibit a more potent hypoglycemic action and a significantly prolonged action time than the corresponding amino derivatives on different levels and are less prone to hypoglycemia. For example, the low dose groups of example compounds I-1-13 all showed a stronger and longer lasting hypoglycemic potential than the linagliptin group with significant differences (p < 0.05).

Claims

1. A compound represented by the following formula (II), a stereoisomer thereof, or a salt thereof:

wherein,

R¹represents C_1-8Alkyl radical, said C_1-8Alkyl can be substituted by R¹²-CO-substituted, and R¹²Represents di (C)_1-6Alkyl) amino, pyrrolidin-1-yl, piperidin-1-yl or C_6-10An aryl group;

R²represents C_1-8Alkyl or C_6-10An aryl group;

R⁵represents hydrogen or represents an amino protecting group.

2. A compound of claim 1, wherein R is¹Represents dimethylaminocarbonylmethyl, pyrrolidin-1-ylcarbonylmethyl, phenylcarbonylmethyl.

3. A compound according to any one of claims 1 or 2, wherein R is²Represents methyl, isopropyl or phenyl.

4. A compound according to any one of claims 1 to 3, wherein R is³Represents 2-methyl-2-propen-1-yl, 2-buten-1-yl, 2, 3-dimethyl-2-buten-1-yl, 2-butyn-1-yl, 1-cyclopenten-1-ylmethyl, 1-cyclohexen-1-ylmethyl, benzyl, 2-cyanobenzyl or 2, 6-dicyanobenzyl.

5. A compound according to any one of claims 1 to 4, wherein R is⁴Represents n-butyl, cyclohexyl, phenyl, piperidinyl or pyridinyl.

6. A compound according to any one of claims 1 to 5 wherein the amino protecting group is selected from methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl, 2-biphenyl-2-propoxycarbonyl, p-toluenesulfonyl, trifluoroacetyl, fluorenylmethoxycarbonyl, allyloxycarbonyl, trimethylsilethoxycarbonyl, phthaloyl, p-toluenesulfonyl, trifluoroacetyl, o-or p-nitrobenzenesulfonyl, pivaloyl, benzoyl, trityl, 2, 4-dimethoxybenzyl, p-methoxybenzyl or benzyl.

7. The compound according to claim 1, selected from:

TABLE 1

8. Use of a compound according to any one of claims 1 to 7 as an intermediate in the manufacture of a medicament for the prevention or treatment of a disease associated with DPP-IV.