Studies on novel polycyclic heterocycles:synthesis of new naphthaquinoxaline and naphthazaquinoxaline derivatives from naturally occurring quinones

摘要

A facile synthesis of novel polycyclic heterocycles namely naphthaquinoxaline and naphthazaquinoxaline derivatives is carried out by the reaction of lapachol and beta-lapachone,naturally occurring naphthoquinones with o-phenylene diamine and 2,3-diaminopyridine.Regioselectivity in the reaction of P-lapachone with 2,3-diaminopyridine is confirmed by single crystal X-ray diffraction of a representative compound 6,7-dihydro-8,8-dimethyl-8H-pyrano[3',2':4]-naphtha[2,1-e]pyrido[2,3-b]pyrazine;C20H17N30,crystallizes as orthorhombic in the space group Pbca with cell parameters a =9.793(3)A,b=17.514(6)A,c=18.334(6)A,V=3144.5(17)A3,Z=8,1.332 mg/m3,R_1=0.3076,WR2=0.3595.