A practical synthesis of 2-((1H-pyrrolo[2,3-b]pyridine-4-yl)methylamino)-5- fluoronicotinic acid

Discovery of the Potent and Selective ATR Inhibitor Camonsertib (RP-3500)

ATR is a key kinase in the DNA-damage response (DDR) that is synthetic lethal with several other DDR proteins, making it an attractive target for the treatment of genetically selected solid tumors. Herein we describe the discovery of a novel ATR inhibitor guided by a pharmacophore model to position a key hydrogen bond. Optimization was driven by potency and selectivity over the related kinase mTOR, resulting in the identification of camonsertib (RP-3500) with high potency and excellent ADME properties. Preclinical evaluation focused on the impact of camonsertib on myelosuppression, and an exploration of intermittent dosing schedules to allow recovery of the erythroid compartment and mitigate anemia. Camonsertib is currently undergoing clinical evaluation both as a single agent and in combination with talazoparib, olaparib, niraparib, lunresertib, or gemcitabine (NCT04497116, NCT04972110, NCT04855656). A preliminary recommended phase 2 dose for monotherapy was identified as 160 mg QD given 3 days/week.

Recent advances in the global ring functionalization of 7-azaindoles

The 7-azaindole building block has attracted considerable interest in the field of drug discovery in the current portfolio. Because of their powerful medicinal properties, the development of synthetic, elegant techniques for the functionalization of 7-azaindoles continues to be an active area of research. Advances in metal-catalyzed chemistry have recently supported the successful development of a number of novel and effective methods for functionalization of the 7-azaindole template. This review reports state-of-the-art functionalization chemistry of 7-azaindoles with an aspiration to highlight the global ring functionalization of 7-azaindoles that are potential as pharmacophores for various therapeutic targets. Other relevant reviews focused on 7-azaindole synthesis, properties and applications have also been reported. However, none of these reviews have been dedicated to the results achieved in the field of metal-catalyzed cross-coupling/C-H bond functionalized reactions. So we wish to discuss and summarize the advances made since 2011 in this field toward 7-azaindole functionalization.

Computational study of the substituent effect of halogenated fused-ring heteroaromatics on halogen bonding

Halogen bonding (XB) has been applied in many fields from crystal engineering to medicinal chemistry. Compared with the well-studied XB of simple halogenated aromatics, little research has been done on the XB of halogenated fused-ring heteroaromatics, a prevalent substructure in organic compounds. With 1H-pyrrolo[3,2-b]pyridines (PPs) as examples of novel fused-ring heteroaromatics with hydrogen bond donor and acceptor and XB donor, the XB formed by the halogenated heteroaromatics was explored in this study. With 4 different substituents, viz., -CH₃, -NH₂, -F, and -CONH₂, at different positions, 339 derivatives of brominated PP (Br-PP) were designed for calculating their electrostatic potential of the σ-hole of the halogen atom (V_S,max) and binding energy with ammonia as XB acceptor (E_int) at M06-2X/6-311++G(d,p) level by PCM model in dichloromethane. The calculated V_S,max values ranging from -1.3 to 35.1 kcal/mol and the calculated E_int ranging from -0.82 to -2.37 kcal/mol demonstrated that the XB is complicated and highly tunable. Noticeably, the electron-withdrawing substituents, especially at ortho-position, do not always increase the values of V_S,max, while the electron-donating substituents do not always decrease V_S,max. Similar results were observed from the calculation on 339 iodinated PPs at M06-2X/6-311++G(d,p) level. The complexity of the XB formed by the halogenated fused ring heteroaromatics indicated a great potential of tuning its strength by different substituents at different positions and revealed a necessity of quantum chemistry calculation for predicting the XB.Graphical abstract.

Pyrrolo[3,2-c]pyridine derivatives with potential inhibitory effect against FMS kinase: in vitro biological studies

A series of eighteen pyrrolo[3,2-c]pyridine derivatives were tested for inhibitory effect against FMS kinase. Compounds 1e and 1r were the most potent among all the other tested analogues (IC₅₀ = 60 nM and 30 nM, respectively). They were 1.6 and 3.2 times, respectively, more potent than our lead compound, KIST101029 (IC₅₀ = 96 nM). Compound 1r was tested over a panel of 40 kinases including FMS, and exerted selectivity against FMS kinase. It was further tested against bone marrow-derived macrophages (BMDM) and its IC₅₀ was 84 nM (2.32-fold more potent than KIST101029 (IC₅₀ = 195 nM)). Compound 1r was also tested for antiproliferative activity against a panel of six ovarian, two prostate, and five breast cancer cell lines, and its IC₅₀ values ranged from 0.15–1.78 µM. It possesses also the merit of selectivity towards cancer cells than normal fibroblasts.

Mechanism of selective C–H cyanation of 2-phenylpyridine with benzyl nitrile catalyzed by CuBr: a DFT investigation

The mechanism of C–H cyanation of 2-phenylpyridine with 2-phenylacetonitrile catalyzed by the CuBr catalyst was elaborated based on DFT calculations.

An efficient transformation of primary halides into nitriles through palladium-catalyzed hydrogen transfer reaction

Two-step one-pot transformation of primary halides into the corresponding nitriles is successfully achieved under mild conditions. In this protocol, acetone functions as both a solvent and a hydrogen acceptor.

Small molecule disruptors of the glucokinase-glucokinase regulatory protein interaction: 4. Exploration of a novel binding pocket

Structure-activity relationship investigations conducted at the 5-position of the N-pyridine ring of a series of N-arylsulfonyl-N'-2-pyridinyl-piperazines led to the identification of a novel bis-pyridinyl piperazine sulfonamide (51) that was a potent disruptor of the glucokinase-glucokinase regulatory protein (GK-GKRP) interaction. Analysis of the X-ray cocrystal of compound 51 bound to hGKRP revealed that the 3-pyridine ring moiety occupied a previously unexplored binding pocket within the protein. Key features of this new binding mode included forming favorable contacts with the top face of the Ala27-Val28-Pro29 ("shelf region") as well as an edge-to-face interaction with the Tyr24 side chain. Compound 51 was potent in both biochemical and cellular assays (IC50=0.005 μM and EC50=0.205 μM, respectively) and exhibited acceptable pharmacokinetic properties for in vivo evaluation. When administered to db/db mice (100 mg/kg, po), compound 51 demonstrated a robust pharmacodynamic effect and significantly reduced blood glucose levels up to 6 h postdose.

Cell-based biological evaluation of a new bisamide FMS kinase inhibitor possessing pyrrolo[3,2-c]pyridine scaffold

A bisamide compound 1 possessing the pyrrolo[3,2-c]pyridine nucleus was synthesized and biologically evaluated. It was tested for kinase inhibitory activity over a panel of 47 kinases, and its selectivity toward the FMS kinase was accidentally discovered. Compound 1 was tested over a panel of seven ovarian, two prostate, and six breast cancer cell lines at a single dose concentration of 10 µM and showed high activity. It was further tested in a 5-dose mode to determine its IC50 and total growth inhibition (TGI) values over the 15 cell lines. Compound 1 showed high potency on the submicromolar scale and good efficacy. The cytotoxic effect of compound 1 over peritoneal macrophages was also investigated. Compound 1 demonstrated higher selectivity against different cancer cell lines compared with HS-27 fibroblasts.

A general, practical palladium-catalyzed cyanation of (hetero)aryl chlorides and bromides

Playing it safe: The nontoxic cyanide source K4 [Fe(CN)6]·3H2O can be used for the cyanation of (hetero)aryl halides. The application of palladacycle catalysts prevents poisoning during catalyst formation, thereby allowing for low catalyst loadings, fast reaction times, and wide heterocyclic substrate scope.

Design, synthesis, and antiproliferative activity of new 1H-pyrrolo[3,2-c]pyridine derivatives against melanoma cell lines. Part 2

A new series of diarylureas and diarylamides possessing 1H-pyrrolo[3,2-c]pyridine scaffold was designed and synthesized. Their in vitro antiproliferative activities against A375P human melanoma cell line and NCI-9 human melanoma cell line panel were tested. All the target compounds, except three amino derivatives 8g, h and 9h, demonstrated superior potencies against A375P to Sorafenib. In addition, compounds 8a and 9b-f demonstrated higher potencies than Vemurafenib against A375P. Compounds 8c and 9b were 7.50 and 454.90 times, respectively, more selective towards A375P melanoma cells over NIH3T3 fibroblasts. Furthermore, compounds 8d, e and 9a-d, f demonstrated very high potencies against the nine tested melanoma cell lines at the NCI. The bisamide derivatives 9a-c, f showed 2-digit nanomolar IC(50) values over different cell lines of the NCI-9 melanoma cell lines.

Recent developments and perspectives in palladium-catalyzed cyanation of aryl halides: synthesis of benzonitriles

The palladium-catalyzed cyanation of Ar-X (X = I, Br, Cl, OTf, and H) allows for an efficient access towards benzonitriles. After its discovery in 1973 and following significant improvements in recent decades, this methodology has become nowadays the most popular for preparation of substituted aromatic nitriles. In this critical review, we summarize the important developments in this area from 2000 until 2010 (151 references).

Design, synthesis, and antiproliferative activity of new 1H-pyrrolo[3,2-c]pyridine derivatives against melanoma cell lines

Synthesis of a new series of diarylureas and diarylamides having 1H-pyrrolo[3,2-c]pyridine scaffold is described. Their in vitro antiproliferative activity against A375P human melanoma cell line was tested and the effect of substituents on pyrrolo[3,2-c]pyridine nucleus was investigated. The newly synthesized compounds, except three N-tolyl derivatives (8f, 9f, and 9h), generally showed superior activity against A375P to Sorafenib. Among all of these derivatives, compounds 8b, 8g, and 9a-e showed the highest potency against A375P with IC(50) in nanomolar range. In addition, compounds 8d, 8e, 8h, 9g, 9i, and 9j were more potent than Sorafenib but with IC(50) in micromolar range. Compounds 8b, 8g, 9b-d, and 9i demonstrated higher selectivity towards A375P compared with NIH3T3 fibroblasts. The most potent diarylurea 8g and diarylamide 9d were further tested and showed high potency over nine melanoma cell lines at the NCI.

A general and convenient catalytic synthesis of nitriles from amides and silanes

A new and convenient protocol for the catalytic dehydration of aromatic and aliphatic amides using silanes in the presence of catalytic amounts of fluoride is presented. The synthesis of aliphatic and aromatic nitriles proceeds with high selectivity under mild conditions. Notably, a wide substrate range is converted in good to excellent yields.