Discovery of a Partial Glucokinase Activator Clinical Candidate: Diethyl ((3-(3-((5-(Azetidine-1-carbonyl)pyrazin-2-yl)oxy)-5-isopropoxybenzamido)-1H-pyrazol-1-yl)methyl)phosphonate (BMS-820132).

Glucokinase (GK) is a key regulator of glucose homeostasis, and its small-molecule activators represent a promising opportunity for the treatment of type 2 diabetes. Several GK activators have been advanced into clinical trials and have demonstrated promising efficacy; however, hypoglycemia represents a key risk for this mechanism. In an effort to mitigate this hypoglycemia risk while maintaining the efficacy of the GK mechanism, we have investigated a series of amino heteroaryl phosphonate benzamides as ''partial" GK activators. The structure-activity relationship studies starting from a "full GK activator" 11, which culminated in the discovery of the "partial GK activator" 31 (BMS-820132), are discussed. The synthesis and in vitro and in vivo preclinical pharmacology profiles of 31 and its pharmacokinetics (PK) are described. Based on its promising in vivo efficacy and preclinical ADME and safety profiles, 31 was advanced into human clinical trials.

Development of the Large-Scale Synthesis of Tetrahydropyran Glycine, a Precursor to the HCV NS5A Inhibitor BMS-986097.

An efficient large-scale synthesis of acid 1, a penultimate precursor to the HCV NS5A inhibitor BMS-986097, along with the final API step are described. Three routes were devised for the synthesis of 1 at the various stages of the program. The third generation route, the one that proved scalable and is the main subject of this paper, features a one-step Michael addition of t-butyl 2-((diphenylmethylene)amino)acetate (24) to (E)-benzyl 4-(1-hydroxycyclopropyl)but-2-enoate (28) followed by cyclization and chiral separation to form 27c, the core skeleton of cap piece 1. The epimerization and chiral resolution of 27c followed by further synthetic manipulations involving the carbamate formation, lactone reduction and cyclization, afforded cyclopropyl pyran 1. A detailed study of diphenylmethane deprotection via acid hydrolysis as well as a key lactone to tetrahydropyran conversion, in order to avoid a side reaction that afforded an alternative cyclization product, are discussed. This synthesis was applied to the preparation of more than 100 g of the final API BMS-986097 for toxicology studies.

Discovery of a Potent Acyclic, Tripeptidic, Acyl Sulfonamide Inhibitor of Hepatitis C Virus NS3 Protease as a Back-up to Asunaprevir with the Potential for Once-Daily Dosing.

The discovery of a back-up to the hepatitis C virus NS3 protease inhibitor asunaprevir (2) is described. The objective of this work was the identification of a drug with antiviral properties and toxicology parameters similar to 2, but with a preclinical pharmacokinetic (PK) profile that was predictive of once-daily dosing. Critical to this discovery process was the employment of an ex vivo cardiovascular (CV) model which served to identify compounds that, like 2, were free of the CV liabilities that resulted in the discontinuation of BMS-605339 (1) from clinical trials. Structure-activity relationships (SARs) at each of the structural subsites in 2 were explored with substantial improvement in PK through modifications at the P1 site, while potency gains were found with small, but rationally designed structural changes to P4. Additional modifications at P3 were required to optimize the CV profile, and these combined SARs led to the discovery of BMS-890068 (29).

Discovery and Preclinical Evaluation of BMS-711939, an Oxybenzylglycine Based PPARα Selective Agonist.

BMS-711939 (3) is a potent and selective peroxisome proliferator-activated receptor (PPAR) α agonist, with an EC50 of 4 nM for human PPARα and >1000-fold selectivity vs human PPARγ (EC50 = 4.5 µM) and PPARδ (EC50 > 100 µM) in PPAR-GAL4 transactivation assays. Compound 3 also demonstrated excellent in vivo efficacy and safety profiles in preclinical studies and thus was chosen for further preclinical evaluation. The synthesis, structure-activity relationship (SAR) studies, and in vivo pharmacology of 3 in preclinical animal models as well as its ADME profile are described.

Discovery of ((4-(5-(Cyclopropylcarbamoyl)-2-methylphenylamino)-5-methylpyrrolo[1,2-f][1,2,4]triazine-6-carbonyl)(propyl)carbamoyloxy)methyl-2-(4-(phosphonooxy)phenyl)acetate (BMS-751324), a Clinical Prodrug of p38α MAP Kinase Inhibitor.

In search for prodrugs to address the issue of pH-dependent solubility and exposure associated with 1 (BMS-582949), a previously disclosed phase II clinical p38α MAP kinase inhibitor, a structurally novel clinical prodrug, 2 (BMS-751324), featuring a carbamoylmethylene linked promoiety containing hydroxyphenyl acetic acid (HPA) derived ester and phosphate functionalities, was identified. Prodrug 2 was not only stable but also water-soluble under both acidic and neutral conditions. It was effectively bioconverted into parent drug 1 in vivo by alkaline phosphatase and esterase in a stepwise manner, providing higher exposure of 1 compared to its direct administration, especially within higher dose ranges. In a rat LPS-induced TNFα pharmacodynamic model and a rat adjuvant arthritis model, 2 demonstrated similar efficacy to 1. Most importantly, it was shown in clinical studies that prodrug 2 was indeed effective in addressing the pH-dependent absorption issue associated with 1.

Synthesis of Biologically Active Piperidine Metabolites of Clopidogrel: Determination of Structure and Analyte Development.

Clopidogrel is a prodrug anticoagulant with active metabolites that irreversibly inhibit the platelet surface GPCR P2Y12 and thus inhibit platelet activation. However, gaining an understanding of patient response has been limited due to imprecise understanding of metabolite activity and stereochemistry, and a lack of acceptable analytes for quantifying in vivo metabolite formation. Methods for the production of all bioactive metabolites of clopidogrel, their stereochemical assignment, and the development of stable analytes via three conceptually orthogonal routes are disclosed.

Identification of 1-{2-[4-chloro-1'-(2,2-dimethylpropyl)-7-hydroxy-1,2-dihydrospiro[indole-3,4'-piperidine]-1-yl]phenyl}-3-{5-chloro-[1,3]thiazolo[5,4-b]pyridin-2-yl}urea, a potent, efficacious and orally bioavailable P2Y(1) antagonist as an antiplatelet agent.

Spiropiperidine indoline-substituted diaryl ureas had been identified as antagonists of the P2Y1 receptor. Enhancements in potency were realized through the introduction of a 7-hydroxyl substitution on the spiropiperidinylindoline chemotype. SAR studies were conducted to improve PK and potency, resulting in the identification of compound 3e, a potent, orally bioavailable P2Y1 antagonist with a suitable PK profile in preclinical species. Compound 3e demonstrated a robust antithrombotic effect in vivo and improved bleeding risk profile compared to the P2Y12 antagonist clopidogrel in rat efficacy/bleeding models.

AlMe(3)-promoted formation of amides from acids and amines.

In the presence of AlMe(3), amines can be directly coupled with acids through dimethylaluminum amide intermediates to form the corresponding amides. A wide range of amines and acids including less nucleophilic amines, bulky amines, unprotected secondary amino acids, and acids with poor solubility were coupled smoothly to give the desired products in 55-98% yields.

Small molecule antagonist of leukocyte function associated antigen-1 (LFA-1): structure-activity relationships leading to the identification of 6-((5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]nonan-7-yl)nicotinic acid (BMS-688521).

Leukocyte function-associated antigen-1 (LFA-1), also known as CD11a/CD18 or alpha(L)beta(2), belongs to the beta(2) integrin subfamily and is constitutively expressed on all leukocytes. The major ligands of LFA-1 include three intercellular adhesion molecules 1, 2, and 3 (ICAM 1, 2, and 3). The interactions between LFA-1 and the ICAMs are critical for cell adhesion, and preclinical animal studies and clinical data from the humanized anti-LFA-1 antibody efalizumab have provided proof-of-concept for LFA-1 as an immunological target. This article will detail the structure-activity relationships (SAR) leading to a novel second generation series of highly potent spirocyclic hydantoin antagonists of LFA-1. With significantly enhanced in vitro and ex vivo potency relative to our first clinical compound (1), as well as demonstrated in vivo activity and an acceptable pharmacokinetic and safety profile, 6-((5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro-[4.4]nonan-7-yl)nicotinic acid (2e) was selected to advance into clinical trials.

Discovery of an oxybenzylglycine based peroxisome proliferator activated receptor alpha selective agonist 2-((3-((2-(4-chlorophenyl)-5-methyloxazol-4-yl)methoxy)benzyl)(methoxycarbonyl)amino)acetic acid (BMS-687453).

An 1,3-oxybenzylglycine based compound 2 (BMS-687453) was discovered to be a potent and selective peroxisome proliferator activated receptor (PPAR) alpha agonist, with an EC(50) of 10 nM for human PPARalpha and approximately 410-fold selectivity vs human PPARgamma in PPAR-GAL4 transactivation assays. Similar potencies and selectivity were also observed in the full length receptor co-transfection assays. Compound 2 has negligible cross-reactivity against a panel of human nuclear hormone receptors including PPARdelta. Compound 2 demonstrated an excellent pharmacological and safety profile in preclinical studies and thus was chosen as a development candidate for the treatment of atherosclerosis and dyslipidemia. The X-ray cocrystal structures of the early lead compound 12 and compound 2 in complex with PPARalpha ligand binding domain (LBD) were determined. The role of the crystal structure of compound 12 with PPARalpha in the development of the SAR that ultimately resulted in the discovery of compound 2 is discussed.

A synthesis of N-bridged 5,6-bicylic pyridines via a mild cyclodehydration using the burgess reagent and discovery of a novel carbamylsulfonylation reaction.

Cyclodehydration using the Burgess reagent provided a novel approach toward the synthesis of N-bridged 5,6-bicylic pyridines including pyrolo-, imidazo-, and triazolopyridines under mild and neutral conditions. The methodology tolerates acid-sensitive functional groups. A novel addition product was observed between the resulting pyrrolo- or imidazopyridine and an additional equivalent of the Burgess reagent, producing the corresponding sulfonylcarbamate adduct.

(3R,5S,E)-7-(4-(4-fluorophenyl)-6-isopropyl-2-(methyl(1-methyl-1h-1,2,4-triazol-5-yl)amino)pyrimidin-5-yl)-3,5-dihydroxyhept-6-enoic acid (BMS-644950): a rationally designed orally efficacious 3-hydroxy-3-methylglutaryl coenzyme-a reductase inhibitor with reduced myotoxicity potential.

3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR) inhibitors, more commonly known as statins, represent the gold standard in treating hypercholesterolemia. Although statins are regarded as generally safe, they are known to cause myopathy and, in rare cases, rhabdomyolysis. Statin-dependent effects on plasma lipids are mediated through the inhibition of HMGR in the hepatocyte, whereas evidence suggests that myotoxicity is due to inhibition of HMGR within the myocyte. Thus, an inhibitor with increased selectivity for hepatocytes could potentially result in an improved therapeutic window. Implementation of a strategy that focused on in vitro potency, compound polarity, cell selectivity, and oral absorption, followed by extensive efficacy and safety modeling in guinea pig and rat, resulted in the identification of compound 1b (BMS-644950). Using this discovery pathway, we compared 1b to other marketed statins to demonstrate its outstanding efficacy and safety profile. With the potential to generate an excellent therapeutic window, 1b was advanced into clinical development.

Acridone-based inhibitors of inosine 5'-monophosphate dehydrogenase: discovery and SAR leading to the identification of N-(2-(6-(4-ethylpiperazin-1-yl)pyridin-3-yl)propan-2-yl)-2- fluoro-9-oxo-9,10-dihydroacridine-3-carboxamide (BMS-566419).

Inosine monophosphate dehydrogenase (IMPDH), a key enzyme in the de novo synthesis of guanosine nucleotides, catalyzes the irreversible nicotinamide-adenine dinucleotide dependent oxidation of inosine-5'-monophosphate to xanthosine-5'-monophosphate. Mycophenolate Mofetil (MMF), a prodrug of mycophenolic acid, has clinical utility for the treatment of transplant rejection based on its inhibition of IMPDH. The overall clinical benefit of MMF is limited by what is generally believed to be compound-based, dose-limiting gastrointestinal (GI) toxicity that is related to its specific pharmacokinetic characteristics. Thus, development of an IMPDH inhibitor with a novel structure and a different pharmacokinetic profile may reduce the likelihood of GI toxicity and allow for increased efficacy. This article will detail the discovery and SAR leading to a novel and potent acridone-based IMPDH inhibitor 4m and its efficacy and GI tolerability when administered orally in a rat adjuvant arthritis model.

Discovery and development of 5-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non-7-yl-methyl]-3-thiophenecarboxylic acid (BMS-587101)--a small molecule antagonist of leukocyte function associated antigen-1.

LFA-1 (leukocyte function-associated antigen-1), is a member of the beta2-integrin family and is expressed on all leukocytes. This letter describes the discovery and preliminary SAR of spirocyclic hydantoin based LFA-1 antagonists that culminated in the identification of analog 8 as a clinical candidate. We also report the first example of the efficacy of a small molecule LFA-1 antagonist in combination with CTLA-4Ig in an animal model of transplant rejection.

Synthesis and biological activity of 5-aryl-4-(4-(5-methyl-1H-imidazol-4-yl)piperidin-1-yl)pyrimidine analogs as potent, highly selective, and orally bioavailable NHE-1 inhibitors.

A series of potent inhibitors of the sodium hydrogen exchanger-1 (NHE-1) is described. Structure-activity relationships identified the 3-methyl-4-fluoro analog 9t as a highly potent (IC50 = 0.0065 microM) and selective (NHE-2/NHE-1=1400) non-acylguanidine NHE-1 inhibitor. Pharmacokinetic studies showed that compound 9t has an oral bioavailability of 52% and a plasma half life of 1.5 h in rats. Because of its promising potency, selectivity, and a good pharmacokinetic profile, compound 9t was selected for further studies.

Discovery of novel 2-(aminoheteroaryl)-thiazole-5-carboxamides as potent and orally active Src-family kinase p56(Lck) inhibitors.

A series of substituted 2-(aminoheteroaryl)-thiazole-5-carboxamide analogs have been synthesized as novel, potent inhibitors of the Src-family kinase p56Lck. Among them, compound 2 displayed superior in vitro potency and excellent in vivo efficacy.

N-(cycloalkylamino)acyl-2-aminothiazole inhibitors of cyclin-dependent kinase 2. N-[5-[[[5-(1,1-dimethylethyl)-2-oxazolyl]methyl]thio]-2-thiazolyl]-4- piperidinecarboxamide (BMS-387032), a highly efficacious and selective antitumor agent.

N-Acyl-2-aminothiazoles with nonaromatic acyl side chains containing a basic amine were found to be potent, selective inhibitors of CDK2/cycE which exhibit antitumor activity in mice. In particular, compound 21 [N-[5-[[[5-(1,1-dimethylethyl)-2-oxazolyl]methyl]thio]-2-thiazolyl]-4-piperidinecarboxamide, BMS-387032], has been identified as an ATP-competitive and CDK2-selective inhibitor which has been selected to enter Phase 1 human clinical trials as an antitumor agent. In a cell-free enzyme assay, 21 showed a CDK2/cycE IC(50) = 48 nM and was 10- and 20-fold selective over CDK1/cycB and CDK4/cycD, respectively. It was also highly selective over a panel of 12 unrelated kinases. Antiproliferative activity was established in an A2780 cellular cytotoxicity assay in which 21 showed an IC(50) = 95 nM. Metabolism and pharmacokinetic studies showed that 21 exhibited a plasma half-life of 5-7 h in three species and moderately low protein binding in both mouse (69%) and human (63%) serum. Dosed orally to mouse, rat, and dog, 21 showed 100%, 31%, and 28% bioavailability, respectively. As an antitumor agent in mice, 21 administered at its maximum-tolerated dose exhibited a clearly superior efficacy profile when compared to flavopiridol in both an ip/ip P388 murine tumor model and in a s.c./i.p. A2780 human ovarian carcinoma xenograft model.

A new strategy for the construction of the imidazo[1,5-a]quinoxalin-4-one ring system and its application to the efficient synthesis of BMS-238497, a novel and potent Lck inhibitor.

A new efficient strategy was developed for the construction of the imidazo[1,5-a]quinoxalin-4-one ring system. The new method involves condensation of o-nitroaniline with glyoxylate in methanol followed by treatment of the resulting alpha-(o-nitroanilino)-alpha-methoxy acetate with tosylmethyl isocyanide (TosMIC) reagent to give 1-(o-nitrophenyl)imidazole-5-carboxylate. Reductive cyclization of the nitro imidazole carboxylate afforded imidazo[1,5-a]quinoxalin-4-one in three steps and 60% overall yield. The new method was successfully applied to the synthesis of BMS-238497, a novel and potent Lck inhibitor.