PDE4 / 7 Dual-Target Inhibitors, Their Preparation Methods and Applications

Abstract

This invention discloses a PDE4 / 7 dual-target inhibitor, its preparation method, and its applications. The compounds of general formula (A) provided by this invention, or their stereoisomers, stable isotope derivatives, or pharmaceutically acceptable salts thereof, exhibit excellent dual PDE4 / 7 inhibitory activity. Compared to traditional single PDE inhibitors, they demonstrate superior pharmacodynamic performance and fewer side effects, overcoming adverse reactions such as severe nausea, vomiting, and gastrointestinal reactions. These compounds can be used to prepare drugs for treating psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease, ankylosing spondylitis, inflammatory bowel disease, etc.

Description

Technical Field

[0001] This invention belongs to the field of drug synthesis, and specifically relates to a PDE4 / 7 inhibitor with a diarylpyrazole skeleton, its preparation method and application. Background Technology

[0002] Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are intracellular second messengers. They are present in many tissue and cellular structures, responsible for intracellular signal transduction, participating in the regulation of various physiological processes, and playing a crucial role in cellular physiological activities. Imbalances in cAMP and cGMP concentrations can lead to various diseases; therefore, maintaining their concentrations at normal levels to ensure the body's health has become a key research focus. Phosphodiesterases (PDEs) are a series of proteases uniquely capable of selectively hydrolyzing cAMP and cGMP in the body. Based on their substrate specificity and enzyme kinetics, PDEs can be divided into 11 families (PDE1-PDE11). Among them, PDE4 plays an important role in degrading inflammatory cells and in lung and nervous system diseases, making it a very important target for drug development. In recent years, PDE4 inhibitors Roflumilast, Apremilast, and Crisaborole have been approved by the FDA for the treatment of chronic obstructive pulmonary disease, psoriatic arthritis, and atopic dermatitis, respectively. However, while these inhibitors have achieved therapeutic effects, they inevitably cause side effects such as severe nausea, vomiting, and gastrointestinal reactions (Front. Pharmacol. 2018, 9, 1048), which greatly limits their application.

[0003] Drugs that inhibit multiple PDE subtypes simultaneously have emerged as a potential strategy to address these issues. Among these, the most frequently reported are dual-target PDE inhibitors targeting one of the PDE4 subtypes, such as PDE3 / 4 and PDE4 / 7 dual-target inhibitors (Bioorganic & Medicinal Chemistry Letters, 2013, 23, 375-381; European Journal of Medicinal Chemistry, 2018, 146, 381-394; European Journal of Medicinal Chemistry, 2018, 158, 517-533).

[0004] Resveratrol is a natural polyphenol compound widely found in red wine, grape skins, and Japanese knotweed. It possesses various biological activities, including anti-inflammatory, antioxidant, antitumor, and neuroprotective effects (Nutritional Neuroscience, 2017, 20, 180-194), and also exhibits some PDE4 inhibitory activity (Oncotarget, 2016, 7, 17380-17392). However, resveratrol's inhibitory effect on PDE4 is not strong enough. Therefore, we conducted medicinal chemistry design on resveratrol to develop a compound with strong PDE4 inhibitory activity and good PDE7 inhibitory activity, which is of great significance and has significant clinical demand and market value. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a compound with good PDE4 / 7 inhibitory activity.

[0006] To achieve the above objectives, the present invention provides a PDE4 / 7 dual-target inhibitor, comprising a compound of general formula (A), or a stereoisomer thereof, a stable isotopic derivative thereof, or a pharmaceutically acceptable salt thereof, as follows:

[0007]

[0008] In the general formula:

[0009] R is:

[0010] The C1-12C alkyl or C1-12C heteroalkyl or C3-12C cycloalkyl or C3-12C cycloheteroalkyl, wherein the C1-12 heteroalkyl or C3-12C cycloheteroalkyl contains the following atoms or functional groups: N, O, S atoms or containing two of them;

[0011] Alternatively, it may be a benzene ring, an aromatic heterocycle, a benzene ring containing a substituent, or an aromatic heterocycle containing a substituent, wherein the substituent is a hydroxyl group, a 1-4C substituted alkyl or alkoxy group, an amino group, a 1-4C substituted alkylamino group, a nitro group, or a cyano group.

[0012] Preferably, R is:

[0013] The C1-6 C alkyl or C1-6 C heteroalkyl or C3-6 C cycloalkyl or C3-6 C cyclohexaalkyl, wherein the C1-6 C heteroalkyl or C3-6 C cyclohexaalkyl contains the following atoms or functional groups: N, O, S atoms or two of them.

[0014] As a preferred option, the PDE4 / 7 dual-target inhibitor is selected from:

[0015]

[0016] The present invention also provides a pharmaceutical composition comprising a compound of general formula (A) as described in any of the preceding claims, or a stereoisomer thereof, a stable isotope derivative thereof, or a pharmaceutically acceptable salt thereof as an active ingredient.

[0017] The present invention also provides a method for preparing a PDE4 / 7 dual-target inhibitor, the preparation steps of which are as follows:

[0018] (1) Dissolve substituted 3,5-dimethoxybenzaldehyde and 1-[4-(diethoxymethyl)phenyl]ethyl ketone in methanol, add 3M sodium hydroxide solution under ice bath conditions, and react. After the reaction is complete, adjust the pH to neutral, add ethyl acetate and water to separate the layers, take the ethyl acetate layer to remove the solvent under reduced pressure, and separate by column chromatography to obtain intermediate product 3.

[0019] (2) Dissolve intermediate product 3, p-toluenesulfonylhydrazine and catalytic amount of iodine in anhydrous ethanol, heat to reflux, and after the reaction is complete, let the reactants stand to precipitate a light yellow solid, recrystallize it in DMF to obtain intermediate product 4.

[0020] (3) At room temperature, intermediate product 4 and 2M hydrochloric acid were dissolved in tetrahydrofuran and stirred. After the reaction was completed, ethyl acetate and water were added to separate the layers. The solvent in the ethyl acetate layer was evaporated under reduced pressure and separated by column chromatography to obtain intermediate product 5.

[0021] (4) Dissolve intermediate 5 and the amine compound in anhydrous ethanol, reflux the reaction, and after the reaction is complete, cool to room temperature. Add sodium borohydride in portions to continue the reaction. After the reaction is complete, evaporate the solvent under reduced pressure, dissolve the reactants in ethyl acetate, filter, wash with saturated brine, separate the ethyl acetate layer, evaporate the solvent under pressure, and separate by column chromatography to obtain the target product. The general formula (A) of the target product is as described above, and the general formula (B) of the amine compound is RNH2. In general formula (B):

[0022] R is:

[0023] The C1-12 C alkyl or C1-12 C heteroalkyl or C1-12 C cycloalkyl or C1-12 C cyclohexaalkyl, wherein the C1-12 heteroalkyl or C1-12 C cyclohexaalkyl contains the following atoms or functional groups: N, O, S atoms or contains two of these atoms;

[0024] Alternatively, it may be a benzene ring, an aromatic heterocycle, a benzene ring containing a substituent, or an aromatic heterocycle containing a substituent, wherein the substituent is a hydroxyl group, a 1-4C substituted alkyl or alkoxy group, an amino group, a 1-4C substituted alkylamino group, a nitro group, or a cyano group.

[0025] Preferably, R is:

[0026] The C1-6 C alkyl or C1-6 C heteroalkyl or C3-6 C cycloalkyl or C3-6 C cyclohexaalkyl, wherein the C1-6 heteroalkyl or C1-6 C cyclohexaalkyl contains the following atoms or functional groups: N, O, S atoms or two of them.

[0027] Preferably, the amine compound is ethylamine, propylamine, cyclopentylamine, cyclohexylamine, benzylamine, tyramine, furfurylamine, or N-(2-aminoethyl)morpholine.

[0028] The present invention further provides the use of the above-mentioned PDE4 / 7 dual-target inhibitor in the preparation of medicaments for the prevention and treatment of PDE4-related diseases.

[0029] Preferably, the PDE4-related diseases refer to psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease, ankylosing spondylitis, and inflammatory bowel disease.

[0030] The present invention has the following advantages:

[0031] By designing medicinal compounds from resveratrol and replacing the double bonds in its structure with a pyrazole ring, a PDE4 and PDE7 inhibitor with excellent activity was successfully discovered. The resveratrol derivative with the pyrazole ring and the structure shown in general formula A provided by this invention exhibits good dual PDE4 / 7 inhibitory activity. Compared with traditional single PDE inhibitors, it demonstrates superior pharmacodynamic performance and fewer side effects. This overcomes side effects such as severe nausea, vomiting, and gastrointestinal reactions. These compounds can be used to prepare drugs for treating psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease, ankylosing spondylitis, inflammatory bowel disease, etc. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to embodiments and effect examples, but this is not intended to limit the scope of the invention.

[0033] Example 1: Preparation and Synthesis of Compound a

[0034] (1) Preparation and synthesis of intermediate 3

[0035] The structural formula of intermediate 3 is as follows:

[0036]

[0037] In a round-bottom flask, 1.66 g (10 mmol) of 3,5-dimethoxybenzaldehyde, 2.22 g (10 mmol) of 1-[4-(diethoxymethyl)phenyl]acetone, and 30 mL of methanol were added. Under ice bath conditions, 4.67 mL (0.56 g NaOH) of 3M sodium hydroxide solution was added. The reaction was continued at room temperature for 12 h. After the reaction was complete, the pH was adjusted to neutral with dilute hydrochloric acid. A suitable amount of ethyl acetate and water were added to separate the layers. The ethyl acetate layer was evaporated under reduced pressure to remove the solvent, and the mixture was separated by column chromatography to obtain intermediate 3 (2.45 g, yield 66.3%).

[0038] 1 H NMR (400MHz, DMSO-d6) δ7.53(d,J=8.6Hz,2H),7.36(m,3H),6.93-6.82(m,3H),6.78(m,1H),6.11(s,1H),3.92(s,6H),3.81(m,4H),1.26(m,6H).HRMS calcd.for C 22 H 27 O5[M+H] + :371.1858,found371.1841.

[0039] (2) Preparation and synthesis of intermediate 4

[0040] The structural formula of intermediate 4 is as follows:

[0041]

[0042] 3.70 g (10 mmol) of compound 3, 1.86 g (10 mmol) of p-toluenesulfonyl hydrazine, a catalytic amount of iodine and 30 mL of anhydrous ethanol were added to a round-bottom flask. The mixture was heated under reflux for 5 h, and the reaction was monitored by TLC. After the reaction was completed, the reactants were allowed to stand overnight to precipitate a pale yellow solid. The solid was recrystallized in DMF to give compound 4 (2.77 g, yield 72.6%).

[0043] 1 H NMR (400MHz, DMSO-d6) δ7.55(d,J=8.7Hz,2H),7.23(m,2H),7.13(d,J=8.7Hz,2H),6.92( m,1H),6.78(m,1H),6.12(s,1H),3.91(s,6H),3.83(m,4H),1.25(m,6H).HRMScalcd.for C 22 H 27 N₂O₄[M+H] + :383.1971,found 383.1987.

[0044] (3) Preparation and synthesis of intermediate 5

[0045] The structural formula of intermediate 5 is as follows:

[0046]

[0047] Compound 4 (3.82 g, 10 mmol), 5 mL of 2 M hydrochloric acid, and 30 mL of tetrahydrofuran were added to a round-bottom flask at room temperature, and the reaction was allowed to proceed for 2 h. After the reaction was complete, ethyl acetate and water were added to separate the layers. The solvent was removed from the ethyl acetate layer under reduced pressure, and the product was separated by column chromatography to obtain the target product 5 (2.47 g, yield 80.2%).

[0048] 1 H NMR(400MHz, DMSO-d6)δ9.92(s,1H),8.07(d,J=8.5Hz,2H),7.62(d,J=8.5Hz,2H),7.13(m,2H),6.97(m,1H),6.85(m,1H),3.89(s,6H).HRMS calcd.for C 18 H 17 N₂O₃[M+H] + :309.1239,found309.1226.

[0049] (4) Preparation of compound a

[0050]

[0051] Compound 5 (3.08 g, 10 mmol), ethylamine (0.45 g, 10 mmol), and 30 mL of anhydrous ethanol were added to a round-bottom flask, and the mixture was refluxed for 2 h. After cooling to room temperature, sodium borohydride (0.19 g, 5 mmol) was added in portions, and the reaction was continued for another 5 h. After the reaction was complete, the solvent was evaporated under reduced pressure. The reactants were dissolved in 50 mL of ethyl acetate, filtered, and washed with saturated brine. The ethyl acetate layer was separated, the solvent was evaporated under pressure, and the product was separated by column chromatography to obtain the target product a (2.47 g, yield 83.6%).

[0052] 1 H NMR (400MHz, DMSO-d6) δ7.56(d,J=8.2Hz,2H),7.38(d,J=16.1Hz,1H),7.16(d,J=16.1Hz,1H),6.93(d,J=8 .2Hz,2H),6.81(s,1H),6.55(s,1H),3.91(s,3H),3.82(s,3H),3.71(s,2H),2.12(m,2H),1.35(m,3H).HRMS calcd.for C 20 H24 N3O2[M+H] + :338.1869,found 338.1852.

[0053] Example 2: Preparation and Synthesis of Compound B

[0054] The structural formula of compound b is as follows:

[0055]

[0056] Compound b was synthesized using the same method as compound a in Example 1, except that propylamine was used instead of ethylamine, with an overall yield of 31.3%.

[0057] 1 H NMR (400MHz, DMSO-d6) δ7.53(d,J=8.1Hz,2H),7.33(d,J=16.3Hz,1H),7.17(d,J=16.3Hz,1H),6.92(d,J=8.1Hz,2 H),6.86(s,1H),6.51(s,1H),3.91(s,3H),3.83(s,3H),3.77(s,2H),2.13(m,2H),1.49(m,2H),1.12(m,3H).HRMS calcd.for C 21 H 26 N3O2[M+H] + :352.2025,found 352.2039.

[0058] Example 3: Preparation and synthesis of compound c

[0059] The structural formula of compound c is as follows:

[0060]

[0061] Compound c was synthesized according to the preparation method of compound a in Example 1, using cyclopentylamine instead of ethylamine, with an overall yield of 28.6%. 1 H NMR (400MHz, DMSO-d6) δ7.52(d,J=8.3Hz,2H),7.37(d,J=16.2Hz,1H),7.1l(d,J=16.2Hz,1H),6.95(d,J=8.3Hz,2H),6.81(s,1H),6 .47(s,1H),3.92(s,3H),3.80(s,3H),3.77(s,2H),3.06(m,1H),1.71(m,2H),1.61(m,2H),1.45(m,2H),1.38(m,2H).HRMScalcd.for C23 H 28 N3O2[M+H] + :378.2182,found378.2173.

[0062] Example 4: Preparation and Synthesis of Compound d

[0063] The structural formula of compound d is as follows:

[0064]

[0065] Compound d was synthesized according to the preparation method of compound a in Example 1, using cyclohexylamine instead of ethylamine, with an overall yield of 26.1%. 1 HNMR (400MHz, DMSO-d6) δ7.51(d,J=8.5Hz,2H),7.37(d,J=16.3Hz,1H),7.11(d,J=16.3Hz,1H),6.95(d,J=8.5Hz,2H),6.80 (m,1H),6.47(m,1H),3.80(s,3H),3.77(m,3H),3.76(s,2H),2.42(m,1H),1.84(m,2H),1.63(m,2H),1.05-1.22(m,6H).HRMS calcd.forC 24 H 30 N3O2[M+H] + :392.2338,found 392.2351.

[0066] Example 5: Preparation and synthesis of compound e

[0067] The structural formula of compound e is as follows:

[0068]

[0069] Compound e was synthesized according to the preparation method of compound a in Example 1, using benzylamine instead of ethylamine, with an overall yield of 33.9%. 1 H NMR (400MHz, DMSO-d6) δ7.52-7.58(m,4H),7.45-7.48(m,3H),7.18(d,J=8.7Hz,2H),6.98(d,J=8.7Hz ,2H),6.89(m,1H),6.55(m,1H),4.23(m,2H),4.11(m,2H),3.84(s,3H),3.80(s,3H),3.77(s,2H).HRMS calcd.for C 25 H 26 N3O2[M+H] +:400.2025,found400.2013.

[0070] Example 6: Preparation and Synthesis of Compound f

[0071] The structural formula of compound f is as follows:

[0072]

[0073] Compound f was synthesized according to the preparation method of compound a in Example 1, using tyramine instead of ethylamine, with an overall yield of 22.7%. 1 H NMR (400MHz, DMSO-d6) δ9.32(s,1H),7.49(d,J=8.6Hz,2H),7.32(d,J=16.2Hz,1H),7.10(d,J=16.2Hz,1H),6.96(m,3H) ,6.82(m,2H),6.61(d,J=8.6Hz,2H),6.45(m,1H),3.80(s,3H),3.78(s,3H),3.75(s,2H),2.71(m,2H),2.59(m,2H).HRMS calcd.forC 26 H 28 N3O3[M+H] + :430.2131,found 430.2147.

[0074] Example 7: Preparation and Synthesis of Compound g

[0075] The structural formula of compound g is as follows:

[0076]

[0077] Compound g was synthesized according to the preparation method of compound a in Example 1, using furfurylamine instead of ethylamine, with an overall yield of 30.2%. 1 H NMR (400MHz, DMSO-d6) δ7.58(m,1H),7.46(d,J=8.6Hz,2H),7.25(m,1H),7.09(m,1H),6.96(d,J =8.6Hz,2H),6.82(m,1H),6.48(m,1H),6.52(m,1H),6.28(m,1H),3.80(s,6H),3.73(m,4H).HRMS calcd.for C 23 H 24 N3O3[M+H] + :390.1818,found 390.1829.

[0078] Example 8: Preparation and Synthesis of Compound h

[0079] The structural formula of compound h is as follows:

[0080]

[0081] Compound g was synthesized according to the preparation method of compound a in Example 1, using N-(2-aminoethyl)morpholine instead of ethylamine, with an overall yield of 30.2%. 1 HNMR(400MHz,DMSO-d6)δ7.55(d,J=8.7Hz,2H),7.32(m,1H),7.13(m,1H),6.95(d,J=8.7Hz,2H),6.82(m,1H), 6.48(m,1H),3.80(s,3H),3.81(s,3H),3.77(m,2H),3.40(m,4H),2.62(m,2H),2.35(m,2H),2.23(m,4H).HRMS calcd.for C 24 H 31 N4O3[M+H] + :423.2396,found 423.2381.

[0082] The PDE4 inhibitory activity of the products obtained in Examples 1-8 was studied.

[0083] Experimental methods: The methods were followed according to existing literature (J.Nat.Prod.2014,77,955-962; Eur.J.Med.Chem.2016,114,134-140; Biochem.Pharmacol.2017,130,51-59). Rolipram was used as the PDE4 positive control, and BRL-50481 as the PDE7 positive control. The solution contained 20 mM Tris / HCl buffer (pH 7.5), 10 mM MgCl2, 1 mM DTT, and 10-30 nM specific fluorescent substrate. 3 The analytical buffer for H-cAMP (20,000-30,000 cpm / assay, GE Healthcare) and the analyte were incubated at room temperature (25°C) for 15 minutes. The reaction was terminated by adding 0.2 M ZnSO4. The reaction product was diluted with 0.2 M Ba(OH)2. 3 H-AMP precipitates out, and unreacted molecules are separated. 3 H-cAMP remained in the supernatant. The radioactivity of the supernatant was determined using a liquid scintillation counter (PerkinElmer 2910 liquid scintillation counter). For IC... 50The determination requires at least eight different concentrations of the analyte. Each measurement must be repeated at least three times. The IC50 value is calculated using a nonlinear regression method. 50 value.

[0084] Table 1. Inhibitory activities of compounds against PDE4 and PDE7

[0085]

[0086]

[0087] From the specific ICs in the table above 50 The data show that compounds of general formula A exhibit strong inhibitory effects on both PDE4 and PDE7 (<5 μM), which are significantly higher than those of resveratrol. Among them, compounds a, b, and c show stronger inhibitory effects on both PDE4 and PDE7 than the positive control. Compounds d and g show stronger inhibitory effects on PDE4 than the positive control and also have strong inhibitory effects on PDE7. Compounds e, f, and h show stronger inhibitory effects on PDE7 than the positive control and also have strong inhibitory effects on PDE4, indicating potential medicinal value.

[0088] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of the present invention in detail, and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A PDE4 / 7 dual-target inhibitor, characterized in that: Comprising a compound of general formula (A), or a pharmaceutically acceptable salt thereof, the general formula (A) is as follows: In the general formula: R is: An alkyl group having 1 - 6 carbon atoms or a cycloalkyl group having 3 - 6 carbon atoms.

2. A PDE4 / 7 dual-target inhibitor, characterized in that, It is selected from: 。 3. A pharmaceutical composition, characterized in that: It contains a PDE4 / 7 dual-target inhibitor as described in claim 1 or 2, or a pharmaceutically acceptable salt thereof as an active ingredient.

4. A method for preparing a PDE4 / 7 dual-target inhibitor, characterized in that: Its preparation steps are as follows: (1) Dissolve 3,5-dimethoxybenzaldehyde and 1-[4-(diethoxymethyl)phenyl]ethanone in methanol, add a 3 M sodium hydroxide solution under ice bath conditions to react. After the reaction is completed, adjust the pH value to neutral, then add ethyl acetate and water for liquid separation. Take the ethyl acetate layer and evaporate the solvent under reduced pressure, and separate by column chromatography to obtain intermediate 3. The structural formula of intermediate 3 is as follows: ； ((2) Dissolve intermediate 3, p-toluenesulfonylhydrazide, and a catalytic amount of iodine in absolute ethanol, heat under reflux. After the reaction is completed, let the reactant stand still to precipitate a light yellow solid, and recrystallize it in DMF to obtain intermediate 4. The structural formula of intermediate 4 is as follows: ； (3) At room temperature, dissolve intermediate 4 and 2 M hydrochloric acid in tetrahydrofuran and stir to react. After the reaction is completed, add ethyl acetate and water for liquid separation. Evaporate the solvent from the ethyl acetate layer under reduced pressure, and separate by column chromatography to obtain intermediate 5. The structural formula of intermediate 5 is as follows: ； (4) Dissolve intermediate 5 and an amine compound in absolute ethanol, reflux to react. After the reaction is completed, cool to room temperature, add sodium borohydride in batches and continue to react. After the reaction is completed, evaporate the solvent under reduced pressure. Dissolve the reactant in ethyl acetate, filter, wash with saturated brine, separate the ethyl acetate layer, evaporate the solvent under reduced pressure, and separate by column chromatography to obtain the target product. The general formula (A) of the target product is as described in claim 1. The general formula (B) of the amine compound is RNH2. In the general formula (B): R is: An alkyl group having 1 - 6 carbon atoms or a cycloalkyl group having 3 - 6 carbon atoms.

5. The method for preparing a PDE4 / 7 dual-target inhibitor according to claim 4, characterized in that, The amine compound is ethylamine, propylamine, cyclopentylamine, cyclohexylamine.

6. Use of a PDE4 / 7 dual-target inhibitor as described in claim 1 or 2 in the preparation of a drug for preventing and treating PDE4-related diseases.

7. The use according to claim 6, characterized in that: The PDE4-related diseases refer to psoriasis, psoriatic arthritis, chronic obstructive pulmonary disease, ankylosing spondylitis, and inflammatory bowel disease.

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