Synthesis of 1-azabenzo[a]phenoxazin-5-one and 11-amino-1,8,10-triazabenzo[a]phenoxazin-5-one and their Functionalized aryl derivatives via Mizoroki-Heck arylation methodology

Abstract

The synthesis of angular 1-azabenzo[a]phenoxazin-5-one and 11-amino-1,8,10-triazabenzo[a] phenoxazin-5-one and their functionalized aryl derivatives via Mizoroki-Heck arylation methodology is reported. 11-Amino-1,8,10-triazabenzo[a]phenoxazin-5-one (16) and 1-azabenzo[a]phenoxazin-5-one (18) were synthesized by the reaction of 7-chloro-5,8-quinolinequinone (obtained by a multistage conversion of 8-hydroxyquinoline) with 4,5-diamino-6-hydroxypyrimidine and 2-aminophenol respectively in the presence of anhydrous sodium acetate. 11-Amino-1,8,10-triazabenzo[a]phenoxazin-5-one and 1-azabenzo[a]phenoxazin-5-one were subjected to Mizoroki-Heck coupling reaction by refluxing with iodobenzene derivatives, using 1,4-bis(diphenylphosphino)butane-palladium(11) chloride as catalyst, 1,4-bis-(2-hydroxy-3,5-ditertbutylbenzyl)piperazine as ligand and methanol as solvent at 60-650C for 4 h to afford in excellent yield aryl derivatives of angular 11-amino-1,8,10-triazabenzo[a]phenoxazin-5-one (19a-c) and 1-azabenzo[a]phenoxazin-5-one (20a-c) respectively. The structures were established by UV/visible, FTIR, proton-NMR and carbon-13 NMR spectral and elemental analysis.