Synthesis and crystal structure of the N4-oxide of an hydroxybenzo[f]quinoxalin-6(5H)-one obtained by oxidative cleavage of beta-lapachone-quinoxaline

Abstract

The N4-oxide of the 5-(3-hydroxy-3-methylbutyl)-5-hydroxybenzo[f]quinoxalin-6(5H)-one was synthesized from beta-lapachone-quinoxaline by MCPBA oxidation and the crystal structure has been determined (C17H18N2O4), Mr=297.3, a=15.880(5), b=16.998(1), c=5.587(2) A, V=1508.1(5) A3, D x=1.31, space group P21212, Z=4, S=1.109 and R obs=0.06. The central ring of the molecule is in a twisted-boat conformation and the molecular packing is done through two intermolecular hydrogen bonds O–H···O [2.072(6)] and [2.177(5) A], forming columns along the direction parallel to the c-axis.