2-(3-Methyl-2-oxoquinoxalin-1-yl)-N-(4-methyl-phen-yl)acetamide.

The quinoxaline moiety in the title mol-ecule, C(18)H(17)N(3)O(2), is not quite planar and the p-tolyl group is rotationally disordered over two nearly equally populated sets of sites. In the crystal, N-H⋯O and C-H⋯O hydro-gen bonds form chains extending along the b-axis direction. Due to the disorder of the p-tolyl rings, short C⋯C distances are observed between adjacent chains.