Diversity Oriented Synthesis of 4H-Pyrimido[2,1-b]benzothiazole Derivatives via Biginellis Reaction: A Review.

BACKGROUND: Heterocycles have extended into widespread use for generating large collection of molecules in multi-component reactions. The development of new strategies for fused pyrimidobenzothiazole system has remained a highly attractive but challenging proposition for scientists working all around. OBJECTIVE: The main objective of this work is to explore the utility of different catalysts as an ecofriendly reaction medium for green Biginellis reaction. METHOD: A detailed study of Biginellis reactions using various catalysts was done using different research tools. The methods involved reaction of equimolar mixture of benzothiazole, 1,3-diketone and aldehyde as reactants by conventional and greener pathways via Knoevenagal condensation. RESULTS: The present review has several significant advantages for the scientists regarding green synthesis viz. green conditions, short reaction times, high yields, clean reaction conditions, easy isolation of products, simple work-up procedure and mild reaction conditions. CONCLUSION: Our report gives an overview of the combinatorial libraries for fused benzothiazole entities using metal catalyst, acid catalyst, ionic liquids, phase transfer catalyst, nano catalyst, etc.

Thiazole Containing Heterocycles with CNS Activity.

BACKGROUND: Thiazoles are promising scaffolds in the area of medicinal and pharmaceutical chemistry and have accounted to show different pharmacophoric properties. For the last years, thiazole derivatives have focused too much attention to develop different new CNS active agents. It has been broadly used to generate diverse therapeutic agents against various CNS targets. Histamine H3 receptors are seriously involved in the pathophysiology of numerous disorders of the central nervous system. METHOD: The literature survey has been done using different database from peerreviewed journals. The quality of repossessed papers was evaluated using standard tools. The details of important papers were described to focus on the potency of thiazole containing heterocycles with CNS activity. RESULT: Eighty nine papers were included in the review indicating thiazole containing heterocycles with CNS activity. (1) to (30) papers included different thiazole derivatives impregnated withCNS activity. Different CNS agents have been shown in references (37) to (56). The remaining papers have been searched for anticonvulsant agents (57) to (78) and other miscellaneous activities from (79) to (89). CONCLUSION: A detailed investigation has been carried out on thiazoles and its derivatives to judge its efficacy to overcome several CNS disorders. This article covers the recent updates of thiazole and its derivative with CNS activity already present in literature and will definitely provide a better platform for the production and development of potent thiazole based CNS vigorous drugs in near future.