Azepines and piperidines with dual norepinephrine dopamine uptake inhibition and antidepressant activity.

Herein, we describe the discovery of inhibitors of norepinephrine (NET) and dopamine (DAT) transporters with reduced activity relative to serotonin transporters (SERT). Two compounds, 8b and 21a, along with nomifensine were tested in a rodent receptor occupancy study and demonstrated dose-dependent displacement of radiolabeled NET and DAT ligands. These compounds were efficacious in a rat forced swim assay (model of depression) and also had activity in rat spontaneous locomotion assay.

De novo design of a picomolar nonbasic 5-HT(1B) receptor antagonist.

We describe herein the discovery of novel, de novo designed, 5-HT(1B) receptor antagonists that lack a basic moiety and that provide improved hERG and in vitro phospholipidosis profiles. We used a known 5-HT(1B) antagonist template as our starting point and focused on replacing the piperazine moiety. Pyrazole-based ideas were designed and synthesized among a small library of piperazine replacements. To our knowledge, these are the first potent, nonbasic, functionally active antagonists of the 5-HT(1B) receptor.

Synthesis and biological evaluation of 1-aryl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-4-one inhibitors of cyclin-dependent kinases.

Using a high-throughput screening strategy, a series of 1-aryl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidin-4-ones was identified that inhibit the cyclin-dependent kinase (CDK) 4/cyclin D1 complex-mediated phosphorylation of a protein substrate with IC(50)s in the low micromolar range. On the basis of preliminary structure-activity relationships (SAR), a model was proposed in which these inhibitors occupy the ATP-binding site of the enzyme, forming critical hydrogen bonds to the same residue (Val96) to which the amino group in ATP is presumed to bind. X-ray diffraction studies on a later derivative bound to CDK2 support this binding mode. Iterative cycles of synthesis and screening lead to a novel series of potent, CDK2-selective 6-(arylmethyl)pyrazolopyrimidinones. Placement of a hydrogen-bond donor in the meta-position on the 6-arylmethyl group resulted in approximately 100-fold increases in CDK4 affinity, giving ligands that were equipotent inhibitors of CDK4 and CDK2. These compounds exhibit antiproliferative effects in the NCI HCT116 and other cell lines. The potency of these antiproliferative effects is enhanced in anilide derivatives and translates into tumor growth inhibition in a mouse xenograft model.

Parallel synthesis of acylsemicarbazide libraries: preparation of potent cyclin dependent kinase (cdk) inhibitors.

Potent cyclin dependent kinase inhibitors were prepared using parallel synthesis methodology. Treating advanced intermediate 2 with a variety of hydrazides in DMSO at 80 degrees C for 30 min gave the desired acylsemicarbazides in good to excellent yield. Several compounds were active against cdk4/D1 and cdk2/E in the low nanomolar range. The SAR indicates a wide variety of substituents are tolerated at the acylsemicarbazide moiety.

Synthesis and evaluation of indenopyrazoles as cyclin-dependent kinase inhibitors. 2. Probing the indeno ring substituent pattern.

We disclose a novel series of indenopyrazole-based cyclin-dependent kinase (CDK) inhibitors. Kinetic experiments confirmed our initial molecular modeling studies that the compounds are competitive with respect to adenosine 5'-triphosphate (ATP) and bind in the kinase ATP pocket. A unique combination of active pharmacophores led us to a series of semicarbazide-based inhibitors that are highly potent against CDK2 and CDK4 while maintaining selectivity against other relevant serine/threonine kinases. These compounds were active against a transformed human colon cancer cell line (HCT116) while maintaining an acceptable margin of activity against a normal fibroblast cell line. The compounds were found to be highly protein bound in our cell-based assay with the exception of 11k, which maintained a reasonable level of activity in the presence of human plasma proteins.

Synthesis and evaluation of indenopyrazoles as cyclin-dependent kinase inhibitors. 3. Structure activity relationships at C3(1,2).

The identification of indeno[1,2-c]pyrazol-4-ones as inhibitors of cyclin-dependent kinases (CDKs) has led to the discovery of a series of novel and potent compounds. Herein, we report the effects of substitutions at C3 of the indeno[1,2-c]pyrazol-4-one core with alkyls, heterocycles, and substituted phenyls. Substitutions at the para position of the phenyl ring at C3 were generally well-tolerated; however, larger groups were generally inactive. For alkyls directly attached to C3, longer chain substituents were not tolerated; however, shorter alkyl groups and cyclic alkyls were acceptable. In general, the heterocycles at C3 gave the most potent analogues. One such heterocycle, 24j, was examined in detail and was determined to have a biological profile consistent with CDK inhibition. An X-ray crystal structure of one of the alkyl compounds, 13q, complexed with CDK2 was determined and showed the inhibitor residing in the adenosine 5'-triphosphate pocket of the enzyme.