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The discovery, synthesis and SAR of a novel series of 3-benzyl-1,3-oxazolidin-2-ones as positive allosteric modulators (PAMs) of mGluR2 is described. Expedient hit-to-lead work on a single HTS hit led to the identification of a ligand-efficient and structurally attractive series of mGluR2 PAMs. Human microsomal clearance and suboptimal physicochemical properties of the initial lead were improved to give potent, metabolically stable and orally available mGluR2 PAMs.

The potency and physical properties of a previously reported 7-oxo-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine series of human eosinophil phosphodiesterase inhibitors were improved by tying the lactam moiety into a triazolo ring. The resulting 5,6-dihydro-(9H)-pyrazolo[3,4-c]-1,2,4-triazolo[4,3-alpha]pyridine series provided nonionizable analogs with melting point properties suitable for micronization. Substitution at the 3-position of the 5,6-dihydro-(9H)-pyrazolo[3,4-c]-1,2,4-triazolo[4,3-alpha]pyridine tricycle led to a 2-thienyl analog, 19 (tofimilast), a potent PDE4 inhibitor with low oral bioavailability and no emesis-associated behaviors in ferrets at plasma concentrations up to 152 ng/mL.

A series of isoxazolyl, oxazolyl, and thiazolylpropionic acid derivatives derived from LDV was found to be a potent antagonist of the α 4 β 1 integrin. The synthesis and SAR leading up to 3-[3-(1-{2-[3-methoxy-4-(3- o -tolyl-ureido)-phenyl]-acetylamino}-3-methyl-butyl)-isoxazol-5-yl]-propionic acid ( 22 ) are reported. In an allergic mouse model, compound 22 was efficacious delivered systemically (58% inhib @ 10 mg/kg, sc) as well as by intra-tracheal instillation (ED 50 =2 μg/kg).

The synthesis and biological properties of a novel series of potent and selective phosphodiesterase type IV (PDE IV) inhibitors are described. These catechol benzimidazoles were designed from rolipram and initial compounds reflected a similarly high affinity for the [ 3 H]rolipram b binding site (500 to 1000X greater affinity for the [ 3 H]rolipram binding site over the PDE IV inhibitory site). However, SAR studies on the 3-alkoxy position revealed that this [ 3 H]rolipram binding site affinity could be attenuated, while potentiating the PDE IV inhibitory activity. This resulted in the 2-indanyl analog 13 which is a potent, selective PDE IV inhibitor with a 15X differential in favor of PDE IV binding.

High throughput screening (HTS) of our compound file provided an attractive lead compound with modest P2X(7) receptor antagonist potency and high selectivity against a panel of receptors and channels, but also with high human plasma protein binding and a predicted short half-life in humans. Multi-parameter optimization was used to address the potency, physicochemical and pharmacokinetic properties which led to potent P2X(7)R antagonists with good disposition properties. Compound 33 (CE-224,535) was advanced to clinical studies for the treatment of rheumatoid arthritis.

A novel series of mGluR2 positive allosteric modulators (PAMs), 1-[(1-methyl-1H-imidazol-2-yl)methyl]-4-phenylpiperidines, is herein disclosed. Structure-activity relationship studies led to potent, selective mGluR2 PAMs with excellent pharmacokinetic profiles. A representative lead compound (+)-17e demonstrated dose-dependent inhibition of methamphetamine-induced hyperactivity and mescaline-induced scratching in mice, providing support for potential efficacy in treating psychosis.

Tumor necrosis factor-α (TNF-α) has been implicated as a key mediator in the progression of rheumatoid arthritis. Inhibitors of phosphodiesterase IV (PDE IV) have been shown to inhibit the production of TNF-α by elevating intracellular levels of cyclic adenosine monophosphate (cAMP). Our efforts in a series of biarylcarboxamides have led to the identification of 8j (CP-353,164) as a potent inhibitor of PDE IV and TNF-α production.

In addition to having desirable inhibitory effects on inflammation, anaphylaxis, and smooth muscle contraction, PDE-IV inhibitors also produce undesirable side effects including nausea and vomiting. In general, compounds that inhibit PDE-IV also potently displace [3H]rolipram from a high-affinity binding site in rat cortex. While this binding site has not been identified, it has been proposed to be an allosteric binding site on the PDE-IV enzyme. Preliminary studies have suggested that the emetic potency of PDE-IV inhibitors is correlated with affinity for the brain rolipram binding site rather than potency at inhibiting PDE-IV enzyme activity. Efforts to eliminate the emetic potential of PDE-IV inhibitors were directed toward developing compounds with decreased [3H]rolipram binding affinity while retaining PDE-IV potency. Thus, a novel series of 4-(3-alkoxy-4-methoxyphenyl)benzoic acids and their corresponding carboxamides were prepared and evaluated for their PDE-IV inhibitory and rolipram binding site properties. Modification of the catechol ether moiety led to phenylbutoxy and phenylpentoxy analogues that provided the desired activity profile. Specifically, 4-[3-(5-phenylpentoxy)-4-methoxyphenyl]-2-methylbenzoic acid, 18, was found to exhibit potent PDE-IV inhibitory activity (IC50 0.41 microM) and possessed 400 times weaker activity than rolipram for the [3H]rolipram binding site. In vivo, compound 18 was efficacious in the guinea pig aerosolized antigen induced airway obstruction assay (ED50 8.8 mg/kg, po) and demonstrated a significant reduction in emetic side effects (ferret, 20% emesis at 30 mg/kg, po).

Sorbinil (1), a spirocyclic hydantoin, is a potent inhibitor of the enzyme aldose reductase. Simulation of the rigid spirocyclic ring orientation found in sorbinil was achieved with nonspirocyclic 5-[5'-chloro-2'-(alkylsulfonyl)-phenyl]hydantoins and 5-[5'-chloro-2'-[(N-alkylamino)sulfonyl]phenyl]hydantoins. The 2'-substituent (SO2R) was sufficiently large to hinder rotation of the hydantoin ring, forcing an orientation similar to that of a spirocyclic hydantoin. Calculated conformational preference, X-ray data, and inhibitory IC50 values for these nonspirocyclic 2'-substituted (SO2R) phenylhydantoins are in accord with what is expected for spirocyclic hydantoins and comparable to those of sorbinil.

Sorbinil (1), a spirocyclic hydantoin, is a potent inhibitor of the enzyme aldose reductase. Simulation of the rigid spirocyclic ring orientation found in sorbinil was achieved with nonspirocyclic 5-[5'-chloro-2'-(alkylsulfonyl)-phenyl]hydantoins and 5-[5'-chloro-2'-[(N-alkylamino)sulfonyl]phenyl]hydantoins. The 2'-substituent (SO2R) was sufficiently large to hinder rotation of the hydantoin ring, forcing an orientation similar to that of a spirocyclic hydantoin. Calculated conformational preference, X-ray data, and inhibitory IC50 values for these nonspirocyclic 2'-substituted (SO2R) phenylhydantoins are in accord with what is expected for spirocyclic hydantoins and comparable to those of sorbinil.

The rearrangement of 2-amino-5-phenacyloxazoles with dimethylamine is described. One such rearrangement provided an unexpected tricyclic product.

The rearrangement of 2-amino-5-phenacyloxazoles with dimethylamine is described. One such rearrangement provided an unexpected tricyclic product.