Solvent controlled synthesis of spiro and nonspiro indolinones with aminonaphthoquinone and pyrazolone moieties.

This study describes the design and synthesis of novel hybrid molecular architectures based on the privileged indolin-2-one (oxindole) scaffold. The research leverages a multi-component reaction strategy, employing isatins, 2-amino-1,4-naphthoquinone, and 5-methyl-2-phenylpyrazolone as key building blocks. The solvent regulated the pathway to the aforementioned chemicals. The later compounds were produced in an acetic acid solvent under reflux conditions, whereas the former compounds were made in an ethanol solvent. Nineteen novel oxindole derivatives were synthesized in high yields, and the structures were undoubtedly identified using their NMR data as well as X-ray analysis.