Water mediated pot, atom, and step economic (PASE) synthesis of pyrimido[4,5-d]pyrimidines using ultrasound and microwave irradiation approaches

Abstract

The functioning, Pot, Atom, and Step Economic (PASE) green chemistry proposition has been approached for the synthesis of pyrimido[4,5-d]pyrimidines by the multicomponent reaction (MCR) of barbituric acid, guanidine, and aldehyde derivatives using water solvent and iodine catalyst through ultrasound and microwave irradiation methods. Reaction optimization was performed by varying solvents, reaction time, the concentration of catalyst, and reaction methods. Microwave irradiation approach using water solvent and iodine catalyst (8 mol%) with 5 min led to offer the highest yield. EWG substituted compound 4 g (4-NO₂, guanidine) [87% (U.S.), 93% (M.W.)] was found to be the highest yielded compound in this study. The greenness of the reaction was estimated by calculating some green chemistry metrics. The metrics approved the proposed protocol as an ideal, green, and sustainable approach.

GRAPHICAL ABSTRACT

Keywords:

• Green chemistry
• microwave irradiation
• pyrimido[4,5-d]pyrimidine
• ultrasound
• water solvent

Acknowledgments

The authors are thankful to the Department of Chemistry, C. U. Shah University, Surendranagar and RK University, Rajkot for supporting the research. The authors are also grateful to Mr. Dashrath Kanzariya, PDPU, Gandhinagar for spectral analyses.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing is not applicable to this article as no new data were created in this study. Physical and Spectral characterization data are available in Supplementary.

Additional information

Funding

This work was funded by SHODH Scholarship (202001260001), Gujarat Government, India.