SYNTHESIS AND REACTIVITY OF PYRROLO[1,2-A]QUINOXALINES - CRYSTAL-STRUCTURE AND AM1 CALCULATION

2-Methylquinoxaline reacts with ethyl bromopyruvate giving 2-substitut ed pyrrolo[l,2-a]quinoxalines. The yield of the condensation depends o n the functionalization of starting materials, and optimization is obt ained with 2-dimethyiamino-3-methylquinoxaline (1c). Reactivity of the resulting pyrrolo[l,2-a]quinoxalines was investigated and supported b y a theoretical approach (AM1 calculation performed with the MOPAC 6.0 software). X-ray analysis of 5 which crystallizes in the monoclinic s ystem, space group P2(1)/n, with a = 9.095(1), b = 8.972(1), c = 17.74 9(3) A, beta = 96.56(1)degrees, is also reported.