A single‐step preparation of thiazolo[5,4‐b]pyridine‐ and thiazolo[5,4‐c]pyridine derivatives from chloronitropyridines and thioamides, or thioureas

Abstract

A one-step synthesis of thiazolo [5,4-b]pyridines from an appropriately substituted chloronitropyridine and thioamide, or thiourea, is presented. In particular, the reaction was used to prepare a large number of 6-nitrothiazolo [5,4-b]pyridine derivatives, bearing hydrogen, alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, and amine substituents at the 2-position. The reaction could also be extended to produce a thiazolo [4,5-c]pyridine derivative and thiazolo [5,4-b]pyridines with alternative substituents on the pyridinoid ring.

Sabinene: A New Green Solvent Used in the Synthesis of Thiazolo[5,4-b]pyridines by Thermal or Microwave Activation

“…These compounds can be synthesised in several ways, depending on the functionalities envisaged, in particular on the 6-membered ring. They can also be synthesised in a single step from a chloronitropyridine and a suitably substituted thioamide or thiourea [39]. We chose to use the one-step method starting from a 3-amino-2-chloropyridine derivative and an isothiocyanate, a synthetic method already used when we investigated laser irradiation as a new activation method in organic synthesis [40].…”

Thiazolo[5,4-b]pyridine Alkaloid and Seven ar-Bisabol Sesquiterpenes Produced by the Endophytic Fungus Penicillium janthinellum

“… 27 , 28 A phytochemical investigation on the EtOAc extract of this fungus led to the isolation of 11 metabolites: janthinedine A ( 1 ), janthinepenes A–G ( 2–8 ), and three known compounds ( 9–11 ). Janthinedine A possesses a thiazolo[5,4- b ]pyridine skeleton 29 and janthinepenes A–G belong to a medicinally interesting class of sesquiterpenes— ar -bisabol sesquiterpenes. 30 , 31 Herein, the detailed isolation and structural elucidation, in addition to the antimicrobial activities, are described.…”

“…janthinellum produces diverse metabolites, including brefeldin A (BFA) derivatives, − alkaloids, − azaphilones, , terpenoids, , meroterpenoids, restricticin derivatives, and heterocyclic dipeptides, , and exhibits extensive antitumoral, ,, antibacterial, ,,, and cytoprotective activities. , A phytochemical investigation on the EtOAc extract of this fungus led to the isolation of 11 metabolites: janthinedine A ( 1 ), janthinepenes A–G ( 2–8 ), and three known compounds ( 9–11 ). Janthinedine A possesses a thiazolo­[5,4- b ]­pyridine skeleton and janthinepenes A–G belong to a medicinally interesting class of sesquiterpenes ar -bisabol sesquiterpenes. , Herein, the detailed isolation and structural elucidation, in addition to the antimicrobial activities, are described.…”