Synthesis and evaluation of a series of aminocyanopyridines as antimicrobial agents

Pyridine: the scaffolds with significant clinical diversity

The nitrogen-bearing heterocycle pyridine in its several analogous forms occupies an important position as a precious source of clinically useful agents in the field of medicinal chemistry research. This privileged scaffold has been consistently incorporated in a diverse range of drug candidates approved by the FDA (Food and Drug Administration). This moiety has attracted increasing attention from several disease states owing to its ease of parallelization and testing potential pertaining to the chemical space. In the next few years, a larger share of novel pyridine-based drug candidates is expected. This review unifies the current advances in novel pyridine-based molecular frameworks and their unique clinical relevance as reported over the last two decades. It highlights an inclination to the use of pyridine-based molecules in drug crafting and the subsequent emergence of several potent and eligible candidates against a range of diversified diseases.

The nitrogen-bearing heterocycle pyridine in its several analogous forms occupies an important position as a precious source of clinically useful agents in the field of medicinal chemistry research.

Pyridine and Pyrimidine Derivatives as Privileged Scaffolds in Biologically Active Agents

Pyridine and pyrimidine derivatives have received great interest in recent pharmacological research, being effective in the treatment of various malignancies, such as myeloid leukemia, breast cancer and idiopathic pulmonary fibrosis. Most of the FDA approved drugs show a pyridine or pyrimidine core bearing different substituents. The aim of this review is to describe the most recent reports in this field, with reference to the newly discovered pyridineor pyrimidine-based drugs, to their synthesis and to the evaluation of the most biologically active derivatives. The corresponding benzo-fused heterocyclic compounds, i.e. quinolines and quinazolines, are also reported.

Solvent-free synthesis of novel steroidal 2-aminopyridines

The synthesis of novel steroidal 3-cyano-2-aminopyridines using enaminonitrile and various primary amines was established under solvent-free condition. Structures of the new compounds were characterized by MS, ¹H and ¹³C NMR data and the structure of 2-aminopyridine of the product 5b was further confirmed by X-ray analysis. The reaction mechanism was proposed on the basis of the key intermediate obtained. The adjacent amine and nitrile groups existed in the final products have the potential for late stage functionalization, which would provide efficient access to steroidal compound collections with structural diversity and complexity.

Synthesis of Some Polysubstituted Nicotinonitriles and Derived Pyrido[2,3-d]pyrimidines asIn VitroCytotoxic and Antimicrobial Candidates

The synthesis of polysubstituted pyridines, in addition to some derived pyrido[2,3-d]pyrimidine ring systems supported with chemotherapeutically active functionalities, is described. They were evaluated for theirin vitrocytotoxic effects against three different human tumor cell lines (human colon carcinoma HT29, hepatocellular carcinoma Hep-G2, and Caucasian breast adenocarcinoma MCF7). Nine compounds displayed variable cytotoxic potential, among which alkylthio analogs33,34, and37emerged as the most active members, being almost twice as active as doxorubicin against the colon carcinoma HT29 cell line. In addition, the same three analogs showed a clear differential cytotoxic profile as they exhibited a marginal inhibitory effect on the growth of the normal nontransformed human foreskin fibroblast Hs27 cell line. Meanwhile, nineteen compounds were able to exhibit significant antibacterial activity against both Gram-positive and Gram-negative bacteria, together with moderate antifungal activities. The pyrido[2,3-d]pyrimidine-2(1H)-thione30together with its alkylthio derivatives33and34stemmed as the most active antimicrobial members being equipotent to ampicillin againstS. aureus,E. coli,andP. aeruginosa,together with a noticeable antifungal activity againstC. albicans.Compounds33and34could be considered as a promising template for possible dual antimicrobial-anticancer candidates.

Enantiopure synthesis of 7-(1-pyrindanyl)propargyl ethers as rasagiline analogues via chemical or enzymatic resolution of 1-pyrindan-7-ol

Enantiopure 7-(1-pyrindanyl)propargyl ethers – rasagiline analogues – were efficiently obtainedviachemical and/or enzymatic resolution of the racemic precursor 1-pyrindan-7-ol.

2-[(5-Methyl-thio-phen-2-yl)methyl-idene]malono-nitrile

There are two independent molecules in the asymmetric unit of the title compound, C9H6N2S, which is an inter-mediate compound of a cardiovascular drug. The two molecules are nearly planar, displaying dihedral angles of 3.5 (2) and 5.7 (2)° between the thiophene ring and the malononitrile moiety. In the crystal, C-H⋯N inter-actions lead to the formation of a sheet structure that packs in a parallel fashion.