Design and synthesis of some thiazolo[3,2-a]benzimidazole quaternary salts of potential antidiabetic

A one-pot synthetic approach for the construction of a thiazolo[3,2-a]benzimidazole-linked quinazoline scaffoldviapalladium-catalyzed reactions

4-(2-Substituted-[1,3]thiazolo[3,2-a]benzimidazol-3-yl)quinazolin-2-amines were prepared by the reaction of 2,4-dichloroquinazoline, terminal alkynes, secondary amines, and 1H-benzo[d]imidazole-2(3H)-thione in the presence of palladium catalyst.

Design and synthesis of some new theophylline derivatives with bronchodilator and antibacterial activities

Methylxanthines especially theophylline have been recognized as potent bronchodilators for the relief of acute asthma for over 65 years. Recently, it was found that bacterial infection plays a role in asthma pathogenesis. Accordingly, the present work involves the synthesis of 6-(4-(un)substituted phenyl)thiazolo[2,3-f]theophyllines 2a-g and different series of 8-(1,2,4-triazol-3-ylmethylthio)theophyllines 6-9. The chemical structures of the target compounds were proved by IR, (1)H NMR, (13)C NMR, EI-MS and HRMS spectroscopic techniques along with elemental analyses. The bronchodilator activity of fifteen compounds was determined in vivo by acetylcholine induced bronchospasm in anaesthetized guinea pigs. Results revealed that all compounds showed moderate to good activity; in addition, five compounds exhibited a bronchodilator activity nearly similar to that of aminophylline as a standard. The antibacterial activity of all the target compounds was investigated in vitro against both Gram-positive and Gram-negative bacterial strains. Results revealed that some compounds showed more potent antibacterial activity than ampicillin as a standard. Acute toxicity study for four target compounds revealed that none of these derivatives showed significant toxicity up to 300 mg/kg. It was found that compound 8c combined both promising bronchodilator and antibacterial activities. This compound could be subjected for further investigations as a new possible candidate in the treatment of bronchial asthma.

Thiazolo[3,2-a]benzimidazoles: synthetic strategies, chemical transformations and biological activities

The present review covers the recent synthetic strategies and chemical transformations of thiazolo[3,2-a]benzimidazoles and it also presents the highlights of the biological activities of these compounds.