Straightforward One-Pot Synthesis of New 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one Derivatives: X-ray Single Crystal Structure and Hirshfeld Analyses

A straightforward one-pot route for the synthesis of a new 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one is reported form the direct hydrazinolysis of triketo ester and hydrazine hydrate in ethanol. 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one was subjected to aza-Michael addition and N-alkylation on reaction with a set of alkylating agents in the presence of K2CO3. Hydrazinolysis of 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one ester to hydrazide and conversion of hydrazide to thiosemicarbazide were successful. X-Ray single crystals analysis and 1H, 13C NMR were used for unambiguous structure confirmation. The O…H, N…H, C…N and C…C in 2, and the N…H, C…N, C…C, C…O and H…H interactions in 6 are the most important in the molecular packing based on Hirshfled analysis. Moreover, the presence of short C…C and C…N contacts in both compounds revealed the presence of π–π stacking interactions.