An Efficient Synthetic Access to Substituted Thiazolyl-pyrazolyl-chromene-2-ones from Dehydroacetic Acid and Coumarin Derivatives by a Multicomponent Approach
Two new series of pyran‐ or coumarin‐substituted thiazolyl‐pyrazole‐chromen‐2‐one derivatives 10a–10d and 11a–11d were efficiently synthesized under environmentally friendly reaction conditions through a convenient one‐pot multicomponent reaction of a heterocyclic bromoacetyl derivative 3 or 4 with...
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Published in | European journal of organic chemistry Vol. 2016; no. 15; pp. 2628 - 2636 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
01.05.2016
WILEY‐VCH Verlag Wiley Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Two new series of pyran‐ or coumarin‐substituted thiazolyl‐pyrazole‐chromen‐2‐one derivatives 10a–10d and 11a–11d were efficiently synthesized under environmentally friendly reaction conditions through a convenient one‐pot multicomponent reaction of a heterocyclic bromoacetyl derivative 3 or 4 with thiosemicarbazide and a substituted 3‐(acetoacetyl)coumarin derivative 5a–5d in anhydrous ethanol. The reaction proceeds through Hantzsch thiazole and Knorr pyrazole syntheses in refluxing ethanol. The key features of this approach are its operational simplicity, the quick access to the desired products, and the good to excellent yields. The structures of the newly synthesized compounds were established by IR spectroscopy, 1H, 13C, and 2D NMR spectroscopy, and mass spectrometry.
Two new series of pyran‐ or coumarin‐substituted (thiazolyl‐pyrazole‐chromen‐2‐ones) may be efficiently accessed from bromoacetyl derivatives of dehydroacetic acid or coumarin, thiosemicarbazide, and substituted 3‐(acetoacetyl)coumarins by green multicomponent reactions. The newly synthesized structures were established by IR spectroscopy, 1H, 13C, and 2D NMR spectroscopy, and mass spectrometry. |
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Bibliography: | istex:0EDCB98273A83391FB8E203338A7D3974054C092 ark:/67375/WNG-W97TMT4G-K ArticleID:EJOC201600173 |
ISSN: | 1434-193X 1099-0690 |
DOI: | 10.1002/ejoc.201600173 |