Design and Preparation of 1H-3, 4-Dihydropyrrolo[1,2-a] Pyrazin-1-One via 1H-3,4-Dihydropyrrolo[1,2-C] [1,4] Oxazin-1-One Route
With 2-pyrrolyltrichloroacetone as major starting material, unreported 1H-3,4-dihydropyrrolo- [1,2-a]pyrazin-1-one was prepared successively by its monoesterification with ethylene glycol, bromine displacement of hydroxy group, cyclization to lactone and its amidation. Unreported 7-aroyl-1H-3,4-dihydropyrrolo[1,2-c][1,4]oxazin-1-one compounds were also synthesized in turn by 2-pyrrolyl-trichloroacetone’s Friedel-Crafts acylation and cyclization. Their structures were characterized by IR, 1H NMR, 13C NMR, MS, HRMS, etc.
Y. E. Guo et al., "Design and Preparation of 1H-3, 4-Dihydropyrrolo[1,2-a] Pyrazin-1-One via 1H-3,4-Dihydropyrrolo[1,2-C] [1,4] Oxazin-1-One Route", Advanced Materials Research, Vols. 343-344, pp. 1242-1247, 2012