Water mediated and Baker’s yeast accelerated novel synthetic protocols for tetrahydrobenzo[a]xanthene-11-ones and pyrazolo[3,4-b]quinolines

Abstract

Water mediated and baker’s yeast catalyzed, efficient synthetic routes have been first time developed for multicomponent cyclocondensations leading to bioactive tetrahydrobenzo[a]xanthene-11-ones (4a–h) and pyrazolo[3,4-b]quinolines (7a–i). The developed protocols are conducted at room temperature and gave better to excellent yields of the titled compounds. The biocatalytical resource, activated baker’s yeast is readily available, and biodegradable. These protocols are more convenient, scalable, and obey most of the green principles also. The developed protocols are cost effective and better in operation than existing ones.

Graphical Abstract

Keywords:

• Baker’s yeast
• tetrahydrobenzo[a]xanthene-11-ones
• pyrazolo[3,4-b]quinolines
• one-pot synthesis
• multicomponent

Acknowledgments

The authors are thankful to Late Professor D. B. Ingle for his invaluable discussions and guidance. The authors are also thankful to SAIF, Central Drug Research Institute (CDRI), Lucknow for spectral analysis. One of the authors, ASC is grateful to Dr. Babasaheb Ambedkar Marathwada University, Aurangabad for financial assistance to carry this work successfully.