Green and Efficient Synthesis of Spiroheterocyclic Compounds from Reactions of Isatins, 3-Amino-1-phenyl-1H-pyrazol-5(4H)-one, and Monocyclic Ketones

Abstract

The reactions of isatins, 3-amino-1-pheyl-1H-pyrazol-5(4H)-one, and monocyclic ketones, have been developed for preparation of spiro[indoline-3,4'-pyrazolo[3,4-b]quinoline]-2,3'(6'H)-dione, spiro[cyclohepta[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3-dione, spiro[cycloocta[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3(6H)-dione, and spiro[cyclo dodeca[b]pyrazolo[4,3-e]pyridine-4,3'-indoline]-2′,3(6H)-dione derivatives in aqueous and acetic acid mixed medium. Studies have shown that water was an excellent medium for this reaction. The significant features of this method are wide substrate scope, high yields, operational simplicity, and minimal environment impact.

Keywords:

• Spiro compounds
• isatins
• 3-amino-1-phenyl-1H-pyrazol-5(4H)-one
• monocyclic ketone
• green synthesis

Disclosure statement

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

Additional information

Funding

We are grateful to the Natural Science Foundation of the Jiangsu Higher Education Institutions of China [No. 21KJB150011, 18KJA150004], and this work was also sponsored by TAPP.