New derivatives of 2,7‐naphthyridine‐3‐carboxylic acid were synthesized. We report the hydrolysis, chlorination, alkylation, and amination of the 2,7‐naphthyridine esters 1, 2. A series of Schiff's bases 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h, 8i, 8j, 9a, 9b, 9b', 9c, 9d, 9e were produced by treating the obtained hydrazides 6 and 7 with aromatic aldehydes. The anticancer activities of the obtained derivatives were examined. Eighteen of the 24 newly synthesized compounds were qualified by the National Cancer Institute NCI (Bethesda, MD, USA) for in vitro screening against 60 different human tumor cell lines. The most active compound 8i was evaluated against a 60‐cell panel at five concentration levels and proved to be most sensitive towards central nervous system cancer (SF‐539), with GI50 = 0.70 µmol, total growth inhibition = 5.41 µmol, and LC50 = 53.7 µmol.

Pyrrolo[3,4-c]pyridine is one of the six structural isomers of the bicyclic ring system containing a pyrrole moiety fused to a pyridine nucleus. The broad spectrum of pharmacological properties of pyrrolo[3,4-c]pyridine derivatives is the main reason for developing new compounds containing this scaffold. This review presents studies on the biological activity of pyrrolo[3,4-c]pyridines that have been reported in the scientific literature. Most of these derivatives have been studied as analgesic and sedative agents. Biological investigations have shown that pyrrolo[3,4-c]pyridines can be used to treat diseases of the nervous and immune systems. Their antidiabetic, antimycobacterial, antiviral, and antitumor activities also have been found.

Marine and terrestrial environments are rich sources of various bioactive substances, which have been used by humans since prehistoric times. Nowadays, due to advances in chemical sciences, new substances are still discovered, and their chemical structures and biological properties are constantly explored. Drugs obtained from natural sources are used commonly in medicine, particularly in cancer and infectious diseases treatment. Naphthyridines, isolated mainly from marine organisms and terrestrial plants, represent prominent examples of naturally derived agents. They are a class of heterocyclic compounds containing a fused system of two pyridine rings, possessing six isomers depending on the nitrogen atom’s location. In this review, biological activity of naphthyridines obtained from various natural sources was summarized. According to previous studies, the naphthyridine alkaloids displayed multiple activities, i.a., antiinfectious, anticancer, neurological, psychotropic, affecting cardiovascular system, and immune response. Their wide range of activity makes them a fascinating object of research with prospects for use in therapeutic purposes.

: 2,7-Naphthyridine is one of the six structural isomers of pyridopyridine. Biological investigations have shown that these compounds have a broad spectrum of activity. They have been found to have antitumor, antimicrobial, analgesic and anticonvulsant effects. The broad spectrum of biological activity of 2,7-naphthyridine derivatives is the main reason for the preparation of new compounds containing this scaffold. This review aims to present various methods of obtaining 2,7-naphthyridine analogs. Compounds containing a 2,7-naphthyridine moiety can be synthesized from a variety of substrates and may be classified into four main categories: those derived from acyclic compounds, from quinoline derivatives, from pyridine derivatives, and from other compounds. Most of them were obtained by the cyclocondensation or intramolecular cyclization of pyridine derivatives. Cyclocondensations of non-cyclic substrates also produced 2,7-naphthyridine derivatives. Tricyclic benzo[2,7]naphthyridines were prepared from quinolines. The 2,7-naphthyridine scaffold has also been synthesized by the rearrangement of pyrrolo[3,4-c]pyridines, pyrano[3,4-c]pyridines or thiopyrano[3,4-c]pyridines.

Fused pyridine derivatives R 0450 Synthesis, Structure, and Pharmacological Screening of 2,7-Naphthyridine Derivatives. -A method for the rearrangement of pyrrolo[3,4-c]pyridines (III) and (VI) into the corresponding 2,7-naphthyridines is developed. Derivative (IV) demonstrates growth inhibition of the ovarian cancer cell line IGROV1. -(WAGNER*, E.; WOJCICKA, A.; BRYNDAL, I.; LIS, T.; Pol.