Synthesis, Antifungal Evaluation of 3-[{(1-aminomethyl) -5,7-dimethyl-2- oxoindolin-3-ylidene} amino]-2-phenylquinazolin-4(3H)-ones and their NLO, MESP, Global Reactivity Descriptor, and AIM Study through DFT Approach

Abstract: A series of fused 3-[{(1-aminomethyl)-5,7-dimethyl-2-oxoindolin-3-ylidene}amino]-2- phenylquinazolin-4(3H)-ones 4(i-ix)) has been designed and synthesized by the condensation reaction between 3-amino -2-phenylquinazolin-4(3H)-one and 5,7-dimethylindolin-2,3-dione, followed by aminomethylation with secondary amines in the presence of formaldehyde and were also screened for their antifungal potential against human pathogenic fungi. The structures of all synthesized compounds have been established with the help of elemental and spectral analysis, such as NMR, FT-IR and mass spectrometry. Out of all synthesized compounds 4(i-ix), theoretical calculation was performed for 3-((5,7-dimethyl-1-(morpholinomethyl)-2-oxoindolin-3-ylidene)amino)-2-phenylquinazolin- 4(3H)-one (4i). The experimental 1H was compared with theoretically calculated values by using B3LYP/6-31G (d, p) level through the GIAO approach. The higher value of first-order hyper polarizability predicted (4i) may be used as NLO material. To explore molecular stability, three intermolecular interactions, such as N8—O22··· H47, C37—H64 ···N12, and C23—H45 ···C30, were observed through the QTAIM approach. In addition, global reactivity descriptor and molecular electrostatic potential were computed for the prediction of reactivity and reactive sites.