A Novel Ionic Liquid Mediated Synthesis of 2,3-Dihydro-1,5-benzothiazepines Using Recyclable Catalyst Amberlyst-15®.

Content Provider	Semantic Scholar
Author	Yadav, Tripti Kumar, Munesh Jain, Renuka Yadav, Ashok Kumar
Copyright Year	2012
Abstract	1,5-Benzothiazepine derivatives have been reported to be well known therapeutic agents due to their wide range of pharmacological 1 and biological activities, such as, anticancer 2 , antibacterial 3 , antifeedant 4 , anticonvulsant 5 , antihypertensive 6 , antidepressant 7 , calcium channel blocker 8 and coronary vasodilator 9 , and also have important role in platelet aggregation 10 . These derivatives have also served as key intermediates for the synthesis of well known drugs, viz., diltiazem 11 , thiazesim 12 and clentiazem 13 . Recently, these derivatives have been found to be among the most potent urease inhibitors 14 . The wide spectrum application of these nuclei has focused a great deal of attention towards the synthesis of these derivatives. The usual procedure 15-17 involved the condensation of α,β-unsaturated ketones or exocyclic α,β-unsaturated ketones with 2-aminothiophenols. Also, some solid support synthesis 18 and microwave assisted synthesis 19,20 of 1,5-benzothiazepines have been reported in the literature. Considerable attention has been paid, world wide, for the replacement of conventional, toxic and polluting Brφnsted and Lewis acid catalysts with ecofriendly recyclable heterogeneous catalysts, viz. zeolites, clays, sulfated zirconia and ion exchange resins 21-23 . Amberlyst-15/70  has been extensively used as an efficient heterogeneous catalyst for many organic transformations 24,25 . Room temperature ionic liquids, especially those based on the 1-n-alkyl-3methylimidazolium cation, have shown tremendous potential as eco-friendly reaction media for variety of organic transformations 26 as they are recyclable, nonvolatile, thermally robust, easy to handle and possess exceptional ability to dissolve a number of organic and organometallic compounds 27 . In view of the above and the continuous interest in the development of ionic liquid promoted synthesis 28-30 , herein is reported, for the first time, an efficient synthesis of 1,5-benzothiazepines using a recyclable catalyst, viz. Amberlyst-15  in environmentally benign ionic liquids, viz. 1-butyl-3-methylimidazolium tetrafluoroborate / triflate / trifluoroacetate [BMIM]BF4/OTf/TFA.
File Format	PDF HTM / HTML
DOI	10.1002/chin.201307168
Volume Number	44
Alternate Webpage(s)	http://nopr.niscair.res.in/bitstream/123456789/14800/1/IJCB%2051B(10)%201447-1451.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article