Discovery of PEGylated 6-Benzhydryl-4-amino-quinazolines as Peripherally Restricted CB1R Inverse Agonists

The 6-benzhydryl-4-amino-quinolin-2-ones are peripherally restricted CB₁ receptor inverse agonists (CB₁RIAs) that have been reported to attenuate obesity and improve insulin sensitivity in the diet-induced obese (DIO) mouse model. However, chronic dosing of select compounds from the series showed time-dependent brain accumulation despite a low brain/plasma exposure ratio. To address this issue, a PEGylation approach was employed to identify a novel series of homodimeric 6-benzhydryl-4-amino-quinazoline-PEG conjugates with an extended half-life. The lead compound 18 engaged peripheral CB₁Rs in a gastrointestinal (GI) tract motility study and demonstrated a high level of peripheral restriction in a chronic DIO mouse pharmacokinetic study.

Synthesis and biological evaluation of benzocyclobutane-C-glycosides as potent and orally active SGLT1/SGLT2 dual inhibitors

Synthesis and biological evaluation of benzocyclobutane-C-glycosides as potent and orally active SGLT1/SGLT2 dual inhibitors are described. Compound 19 showed high inhibitory potency at SGLT1 (IC₅₀ = 45 nM), and excellent potency at SGLT2 (IC₅₀ = 1 nM). It also displayed excellent PK profiles in mice, rats, dogs and monkeys (F = 78-107%). In SD rats, compound 19 treatments significantly reduced blood glucose levels in a dose-dependent manner. In ZDF rats, compound 19 displayed anti-hyperglycemic effect up to 24 h. Therefore, compound 19 may serve as valuable pharmacological tool, and potential use as a treatment for metabolic syndrome.

Discovery of N-arylpyrroles as agonists of GPR120 for the treatment of type II diabetes

The discovery of a novel series of N-arylpyrroles as agonists of GPR120 (FFAR4) is discussed. One lead compound is a potent GPR120 agonist, has good selectivity for related receptor GPR40 (FFAR1), has acceptable PK properties, and is active in 2 models of Type 2 Diabetes in mice.

Discovery of an Isothiazole-Based Phenylpropanoic Acid GPR120 Agonist as a Development Candidate for Type 2 Diabetes

We have discovered a novel series of isothiazole-based phenylpropanoic acids as GPR120 agonists. Extensive structure-activity relationship studies led to the discovery of a potent GPR120 agonist 4x, which displayed good EC₅₀ values in both calcium and β-arrestin assays. It also presented good pharmaceutical properties and a favorable PK profile. Moreover, it demonstrated in vivo antidiabetic activity in C57BL/6 DIO mice. Studies in WT and knockout DIO mice showed that it improved glucose handling during an OGTT via GPR120. Overall, 4x possessed promising antidiabetic effect and good safety profile to be a development candidate.

Discovery of Orally Efficacious Tetrahydrobenzimidazoles as TGR5 Agonists for Type 2 Diabetes

We have discovered a novel series of tetrahydrobenzimidazoles 3 as TGR5 agonists. Initial structure-activity relationship studies with an assay that measured cAMP levels in murine enteroendocrine cells (STC-1 cells) led to the discovery of potent agonists with submicromolar EC₅₀ values for mTGR5. Subsequent optimization through methylation of the 7-position of the core tetrahydrobenzimidazole ring resulted in the identification of potent agonists for both mTGR5 and hTGR5 (human enteroendocrine NCI-H716 cells). While the lead compounds displayed low to moderate exposure after oral dosing, they significantly reduced blood glucose levels in C57 BL/6 mice at 30 mg/kg and induced a 13-22% reduction in the area under the blood glucose curve (AUC)_0-120 min in oral glucose tolerance tests (OGTT).

Evaluation of anti-diabetic effect and gall bladder function with 2-thio-5-thiomethyl substituted imidazoles as TGR5 receptor agonists

A novel series of 2-thio-5-thiomethyl substituted imidazoles was discovered to be potent TGR5 agonists that possessed glucose-lowering effects while inhibiting gall bladder emptying in mice.

Synthesis of β-Substituted Cyclic Enones via Phosphonium Salt-Activated, Palladium-Catalyzed Cross-Coupling of Cyclic 1,3-Diones

Phosphonium salt-activated, Pd-catalyzed Suzuki-Miyaura and Sonogashira cross-coupling reactions of cyclic 1,3-diones in the synthesis of β-substituted cyclic enones are described. These transformations exhibit good isolated yield and high generality with respect to both substrates and coupling partners. Extension of the substrate scope to cyclic 1,3-dione equivalents, such as 2-cyanocyclohexanone (4), is also briefly examined.

Direct dehydrative cross-coupling of tautomerizable heterocycles with alkynes via Pd/Cu-catalyzed phosphonium coupling

The first chemoselective direct dehydrative cross-coupling of tautomerizable heterocycles with alkynes has been achieved via C-H/C-OH bond activations with direct C(sp(2))-C(sp) bond formation, which is in line with ideal synthesis using readily available materials.

Synthesis and discovery of 2,3-dihydro-3,8-diphenylbenzo[1,4]oxazines as a novel class of potent cholesteryl ester transfer protein inhibitors

2,3-Dihydro-3,8-diphenylbenzo[1,4]oxazines were identified as a new class of potent cholesteryl ester transfer protein inhibitors. The most potent compound 6a (IC50=26 nM) possessed a favorable pharmacokinetic profile with good oral bioavailability in rat (F=53%) and long human liver microsome stability (t(1/2)=62 min). It increased HDL-C in human CETP transgenic mice and high-fat fed hamsters. The structure and activity relationship of this series will be described in this Letter.

Design, synthesis, and biological evaluation of (2R,alphaS)-3,4-dihydro-2-[3-(1,1,2,2-tetrafluoroethoxy)phenyl]-5-[3-(trifluoromethoxy)-phenyl]-alpha-(trifluoromethyl)-1(2H)-quinolineethanol as potent and orally active cholesteryl ester transfer protein inhibitor

With the goal of identifying a CETP inhibitor with high in vitro potency and optimal in vivo efficacy, a conformationally constrained molecule was designed based on the highly potent and flexible 13. The synthetic chemistry efforts led to the discovery of the potent and selective 12. In high-fat fed hamsters, human CETP transgenic mice, and cynomolgus monkeys, the in vivo efficacy of 12 for raising HDL-C was demonstrated to be comparable to torcetrapib.

Pd-catalyzed direct arylation of tautomerizable heterocycles with aryl boronic acids via C-OH bond activation using phosphonium salts

The first direct arylation via C-OH bond activation of tautomerizable heterocycles has been achieved using phosphonium salts, on the basis of a combination of the phosphonium coupling and Suzuki-Miyaura cross-coupling conditions. Optimal reaction condition is obtained through screening of phosphonium salts, Pd catalysts, and bases. The direct arylation via C-OH bond activation tolerates a variety of tautomerizable heterocycles and aryl boronic acids. The mechanism of the Pd-catalyzed phosphonium coupling is proposed to proceed via a domino seven-step process including the unprecedented heterocycle-Pd(II)-phosphonium species. Application of the Pd-catalyzed direct arylation via C-OH bond activation using PyBroP leads to the most efficient synthesis of the biologically important 6-arylpurine ribonucleoside in a single step from unactivated and unprotected inosine.

Synthesis and identification of [1,2,4]thiadiazole derivatives as a new series of potent and orally active dual agonists of peroxisome proliferator-activated receptors alpha and delta

Cardiovascular disease is the most common cause of morbidity and mortality in developed nations. To effectively target dyslipidemia to reduce the risk of cardiovascular disease, it may be beneficial to activate the peroxisome proliferator-activated receptors (PPARs) PPARalpha and PPARdelta simultaneously through a single molecule. Replacement of the methylthiazole of 5 (the PPARdelta selective agonist) with [1,2,4]thiadiazole gave compound 13, which unexpectedly displayed submicromolar potency as a partial agonist at PPARalpha in addition to the high potency at PPARdelta. Optimization of 13 led to the identification of 24 as a potent and selective PPARalpha/delta dual agonist. Compound 24 and its close analogs represent a new series of PPARalpha/delta dual agonists. The high potency, significant gene induction, excellent PK profiles, and good in vivo efficacies in three animal models may render compound 24 as a valuable pharmacological tool in elucidating the complex roles of PPARalpha/delta dual agonists and as a potential treatment of the metabolic syndrome.

Synthesis and biological evaluation of 3-aryl-3-(4-phenoxy)-propionic acid as a novel series of G protein-coupled receptor 40 agonists

High-throughput screening of a subset of the J&J compound library containing the carboxylic acid functional group uncovered a bromophenyl derivative as a moderate potent GPR40 agonist. Chemical elaboration of this bromophenyl led to the discovery of a novel series of GPR40 agonists with submicromolar potency. Among them, 22 and 24 behaved as full agonists when compared to the endogenous GPR40 ligand linolenic acid in a functional Ca+2 flux assay in HEK cells expressing GPR40 receptor. Several GPR40 agonists have also demonstrated the ability to induce glucose-mediated insulin secretion in the mouse MIN6 pancreatic beta-cell line. Our data supports the hypothesis that GPR40 may play an important role in fatty acid-mediated glucose-dependent insulin secretion. Compound 22 exhibited good pharmacokinetic profile in rat and may serve as a good candidate for in vivo study and may help to determine if GPR40 agonists would be beneficial in the treatment of type II diabetes.

Discovery of para-alkylthiophenoxyacetic acids as a novel series of potent and selective PPARdelta agonists

A novel series of potent and selective PPARdelta agonists, para-alkylthiophenoxyacetic acids, was identified. The synthesis and structure-activity relationships are described.

An Azomethine Ylide Approach to Complex Alkaloid-like Heterocycles

The nitrone above is readily available via the intramolecular aza Diels-Alder reaction of an amino acid derived triene in acetic acid. Subsequent treatment of the nitrone in refluxing toluene with substituted actetylenes produced the pictured pyrrole. At lower temperatures a 2,3-dihydroisoxazole, which is the product of a 3+2 dipolar cycloaddition, is produced. Upon heating in refluxing toluene the 2,3-dihydroisoxazole is converted to the pyrrole.

Simplified staurosporine analogs as potent JAK3 inhibitors

Simplification of bottom ring and regioselective functionalization of the indolocarbazole unit of staurosporine (2) are described. The modification led to a new series of simplified staurosporine analogs, which exhibited significant inhibitory activity against Janus kinase 3 (JAK3). The structure-activity relationships (SAR) are discussed and a proposed binding model is also highlighted.

Cross-Metathesis Assisted by Microwave Irradiation

Microwave irradiation effectively accelerates cross-coupling metathesis reactions between deactivated olefins. Reactions have been carried out with the phosphine-free Hoveyda-Grubbs catalyst and the "second generation Grubbs' catalyst." While there have been reports that a "microwave effect" is observed in various transformations, the accelerations we observe are due to the efficient and rapid heating and increased pressure in the microwave apparatus.

1-Acyl-1H-[1,2,4]triazole-3,5-diamine analogues as novel and potent anticancer cyclin-dependent kinase inhibitors: synthesis and evaluation of biological activities

A series of 1-acyl-1H-[1,2,4]triazole-3,5-diamine analogues were synthesized as cyclin-dependent kinase (CDK) inhibitors. These compounds showed potent and selective CDK1 and CDK2 inhibitory activities and inhibited in vitro cellular proliferation in various human tumor cells. Representative compound 3b demonstrated in vivo efficacy in a human melanoma A375 xenograft model in nude mice.

Synthesis and identification of [1,3,5]triazine-pyridine biheteroaryl as a novel series of potent cyclin-dependent kinase inhibitors

On the basis of previous studies, we identified pyrazine-pyridine A as a potent vascular endothelial growth factor inhibitor and pyrimidine-pyridine B as a moderately potent cyclin dependent kinase (CDK) inhibitor. A proposed combination of CGP-60474 and compound B led to the discovery of [1,3,5]triazine-pyridine as a new series of potent CDK inhibitors. Palladium-catalyzed C-C bond formation reactions, particularly the Negishi coupling reaction, were used to assemble various triazine-heteroaryl analogues effectively. Among them, compound 20 displayed high inhibitory potency at CDK1 (IC(50) = 0.021 microM), CDK2, and CDK5 and submicromolar potency at CDK4, CDK6, and CDK7. Compound 20 also displayed high potency at GSK-3beta. It demonstrated potent antiproliferative activity on various tumor cell lines, including HeLa, HCT-116, U937, and A375. When 20 was administered intraperitoneally at 150 and 125 mg/kg to nude mice bearing human A375 xenografts, the compound produced a significant survival increase. Molecular docking studies were conducted in an attempt to enhance the understanding of the observed structure-activity relationship.

Synthesis and Structure−Activity Relationships of Pyrazine-Pyridine Biheteroaryls as Novel, Potent, and Selective Vascular Endothelial Growth Factor Receptor-2 Inhibitors

There is much evidence that direct inhibition of the kinase activity of vascular endothelial growth factor receptor-2 (VEGFR-2) will result in the reduction of angiogenesis and the suppression of tumor growth. Palladium-catalyzed C-C bond, C-N bond formation reactions were used to assemble various pyrazine-pyridine biheteroaryls as potent VEGFR-2 inhibitors. Among them, 4-{5-[6-(3-chloro-phenylamino)-pyrazin-2-yl]-pyridin-3-ylamino}-butan-1-ol (39) and N-{5-[6-(3-chloro-phenylamino)-pyrazin-2-yl]-pyridin-3-yl}-N',N'-dimethyl-ethane-1,2-diamine (41) exhibited the highest kinase selectivity against fibroblast growth factor receptor kinase, platelet-derived growth factor receptor kinase, and glycogen synthase kinase-3. All of these compounds showed good cellular potency to inhibit VEGF-stimulated proliferation of human umbilical vein endothelial cells (HUVEC) but with modest effects on the unstimulated growth of HUVEC. The low inhibition of these compounds to the growth of tumor cell lines, such as HeLa, HCT-116, and A375 further confirms that these VEGFR-2 inhibitors are not cytotoxic agents. The in vivo antitumor activity of 39 and 41 were demonstrated in the A375 human melanoma xenograft nude mice model. Molecular modeling (QSAR analysis) was conducted in an attempt to rationalize the observed structure-activity relationship.

Synthesis and discovery of pyrazine-pyridine biheteroaryl as a novel series of potent vascular endothelial growth factor receptor-2 inhibitors

Pathological angiogenesis is associated with disease states such as cancer, diabetic retinopathy, rheumatoid arthritis, endometriosis, and psoriasis. There is much evidence that direct inhibition of the kinase activity of vascular endothelial growth factor receptor-2 (VEGFR-2) will result in the reduction of angiogenesis and the suppression of tumor growth. Attempts to optimize a cyclin-dependent kinase-1 (CDK1) inhibitor by using palladium-catalyzed C-C bond, C-N bond formation reactions to assemble diverse biheteroaryl molecules led to the unexpected discovery of a pyrazine-pyridine biheteroaryl as a novel series of potent VEGFR-2 inhibitors. Compound 15, which had IC(50) = 0.084 microM at VEGFR-2, showed very modest selectivity against fibroblast growth factor receptor-2 (IC(50) = 0.21 microM), platelet-derived growth factor receptor (IC(50) = 0.36 microM), and glycogen synthase kinase-3 (IC(50) = 0.478 microM), while it exhibited more than 10-fold selectivity against epidermal growth factor receptor (IC(50) = 1.36 microM) and insulin-R kinase (IC(50) = 1.69 microM). On the other hand, compound 15 exhibited more than 100-fold selectivity against calmodulin kinase 2; casein kinase-1 and -2; CDK1 and -4; mitogen-activated protein kinase; and protein kinase A, Cbeta2, and Cgamma (IC(50) >10 microM). Compound 15 also displayed high inhibitory potency on VEGF-stimulated human umbilical vein endothelial cell (HUVEC) proliferation (IC(50) = 0.005 microM) and good selectivity against cell lines such as HUVEC, human aortic smooth muscle cells, and MRC5 lung fibroblasts. Molecular docking studies were conducted in an attempt to rationalize the unexpected high VEGFR-2 selectivity of 15.

3-Acyl-2,6-diaminopyridines as cyclin-dependent kinase inhibitors: synthesis and biological evaluation

A novel series of 2,6-diamino-3-acylpyridines were designed and synthesized as cyclin-dependent kinase (CDK) inhibitors. The representative compounds 2r and 11 showed potent CDK1 and CDK2 inhibitory activities and inhibited cellular proliferation in HeLa, HCT116, and A375 tumor cells.

Efficient Conversion of Biginelli 3,4-Dihydropyrimidin-2(1H)-one to Pyrimidines via PyBroP-Mediated Coupling

An efficient two-step procedure is described to convert the Biginelli 3,4-dihydropyrimidin-2(1H)-one to various multifunctionalized pyrimidines via the Kappe dehydrogenation and a new mild PyBroP-mediated coupling with C, N, O, and S nucleophiles, which provides a readily accessible multifunctionalized pyrimidine template for diversity-oriented synthesis.

Design, synthesis, and biological evaluation of novel 7-azaindolyl-heteroaryl-maleimides as potent and selective glycogen synthase kinase-3beta (GSK-3beta) inhibitors

Two approaches were developed to synthesize the novel 7-azaindolyl-heteroarylmaleimides. The first approach was based upon the palladium-catalyzed Suzuki cross-coupling or Stille cross-coupling of 2-chloro-maleimide 5 with various arylboronic acids or arylstannanes. The second approach was based upon the condensation of ethyl 7-azaindolyl-3-glyoxylate 12 with various acetamides. The hydroxypropyl-substituted 7-azaindolylmaleimide template was first used to screen different heteroaryls attached to the maleimide. Replacement of hydroxypropyl with different chain lengths and different functional groups were studied next. Many compounds synthesized were demonstrated to have high potency at GSK-3beta, good GS activity in HEK293 cells and good to excellent metabolic stability in human liver microsomes. Three representative compounds (21, 33, and 34) were demonstrated to have good selectivity against a panel of 80 kinase assays. Among them, compound 33 exhibited very weak inhibitions at the other 79 kinase assays, and behaved as a highly selective GSK-3beta inhibitor.

Synthesis and evaluation of spirobenzazepines as potent vasopressin receptor antagonists

A novel series of spirobenzazepines was synthesized and evaluated for V1a and V2 receptor antagonist activity. Compounds 8b, 8i, and 8k have shown selective V1a receptor antagonist activity. Compounds 8p and 8q were shown to be dual V1a/V2 receptor antagonists.

Synthesis and biological evaluation of novel macrocyclic bis-7-azaindolylmaleimides as potent and highly selective glycogen synthase kinase-3 beta (GSK-3 beta) inhibitors

Palladium catalyzed cross-coupling reactions were used to synthesize two key intermediates 3 and 5 that resulted in the synthesis of novel series of macrocyclic bis-7-azaindolylmaleimides. Among the three series of macrocycles, the oxygen atom and thiophene containing linkers yielded molecules with higher inhibitory potency at GSK-3 beta (K(i)=0.011-0.079 microM) while the nitrogen atom containing linkers yielded molecules with lower potency (K(i)=0.150->1 microM). Compound 33 and 36 displayed 1-2 orders of magnitude selectivity at GSK-3 beta against CDK2, PKC beta II, Rsk3 and little or no inhibitions to the other 62 protein kinases. Compound 46 was at least 100-fold more selective towards GSK-3 beta than PKC beta II, and it had little or no activity against a panel of 65 protein kinases, almost behaved as a GSK-3 beta 'specific inhibitor'. All three compounds showed good potency in GS assay. Molecular docking studies were conducted in an attempt to rationalize the GSK-3 beta selectivity of azaindolylmaleimides. The high selectivity, inhibitory potency and cellular activities of these non-crown-ether typed molecules may provide them as a valuable pharmacological tools in elucidating the complex roles of GSK-3 beta in cell signaling pathways and the potential usage for the treatment of elevated level of GSK-3 beta involved diseases.

Novel non-peptidic neuropeptide Y Y2 receptor antagonists

Through SAR studies of a piperidinylindoline cinnamide HTS lead, the first potent, non-peptide, low molecular weight selective Neuropeptide Y Y2 (NPY Y2) antagonists have been synthesized. The SAR studies around the piperidinyl, the indolinyl, and the cinnamyl moieties are discussed.

2,5-disubstituted 3,4-dihydro-2H-benzo[b][1,4]thiazepines as potent and selective V2 arginine vasopressin receptor antagonists

A number of 2,5-disubstituted benzothiazepines were synthesized and screened for their ability to inhibit arginine vasopressin binding to the human V(2) and V(1a) receptor subtypes. The more active compounds were subsequently analyzed for their antagonist activity in in vitro functional assays. The SAR showed a preference for an acidic unit appended from the benzothiazepine scaffold. This substitution pattern afforded the most potent and selective analogues in the series. The carboxymethyl analogue 4, showed a 140-fold greater selectivity for the V(2) over the V(1a) receptor in the binding assay. In the cell-based functional assays this analogue was a potent and selective antagonist of the V(2) receptor. The in vitro SAR of the series and a description of the in vivo studies around compound 4 is described.

Synthesis and evaluation of nonpeptide substituted spirobenzazepines as potent vasopressin antagonists

A series of substituted spirobenzazepines was prepared and evaluated as V(1a) and V(2) dual vasopressin receptor antagonists. Compounds 7p and 7q have been shown to be not only potent inhibitors of vasopressin receptors, but also have exhibited an excellent overall pharmaceutical suitability profile.

Interesting Behavior of α,β-Unsaturated Oximes in Intramolecular [4 + 2] Cycloaddition Reactions

[structure: see text] Intramolecular [4 + 2] cycloaddition using alpha,beta-unsaturated oximes was explored. The reactions proceeded under unusually facile conditions to furnish the nitrones. The latter were subsequently reacted with DMAD to afford [3 + 2] cycloaddition products.

Synthesis and discovery of macrocyclic polyoxygenated bis-7-azaindolylmaleimides as a novel series of potent and highly selective glycogen synthase kinase-3beta inhibitors

Attempts to design the macrocyclic maleimides as selective protein kinase C gamma inhibitors led to the unexpected discovery of a novel series of potent and highly selective glycogen synthase kinase-3beta (GSK-3beta) inhibitors. Palladium-catalyzed cross-coupling reactions were used to synthesize the key intermediates 17 and 22 that resulted in the synthesis of novel macrocycles. All three macrocyclic series (bisindolyl-, mixed 7-azaindoleindolyl-, and bis-7-azaindolylmaleimides) were found to have submicromolar inhibitory potency at GSK-3beta with various degrees of selectivity toward other protein kinases. To gain the inhibitory potency at GSK-3beta, the ring sizes of these macrocycles may play a major role. To achieve the selectivity at GSK-3beta, the additional nitrogen atoms in the indole rings may contribute to a significant degree. Overall, the bis-7-azaindolylmaleimides 28 and 29 exhibited little or no inhibitions to a panel of 50 protein kinases. Compound 29 almost behaved as a GSK-3beta specific inhibitor. Both 28 and 29 displayed good potency in GS cell-based assay. Molecular docking studies were conducted in an attempt to rationalize the GSK-3beta selectivity of azaindolylmaleimides.

Arylpiperazine substituted heterocycles as selective alpha(1a) adrenergic antagonists

Antagonists of the alpha(1)-adrenergic receptors (alpha(1)-ARs) are useful for the treatment of benign prostatic hyperplasia. A series of potent and subtype-selective alpha(1a)-AR antagonists has been synthesized, displaying in vitro binding affinity in the low the nanomolar range.

Novel thiophene derivatives for the treatment of benign prostatic hyperplasia

The syntheses and biological activities of a novel series of 2,4- and 2,5-disubstituted thiophenes are reported. These analogues have shown excellent affinity and selectivity against alpha(1)-adrenoreceptor subtypes.