The First and Reliable Synthesis of Thieno[2,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-ones via Their [4,3-c] Compounds by Dimroth Rearrangement
作者:Tomohisa Nagamatsu、Shoeb Ahmed
DOI:10.3987/com-05-10518
日期:——
This paper describes a reliable and general synthesis of thieno[2,3-e]-[1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one (5a) and its 2-substitutedderivatives (5b-i) as a novel ring system prepared by nimble isomerization of their [4,3-c] compounds (4a-i), which were produced by condensation of 4-hydrazinothieno-[3,2-d]pyrimidin-2(1H)-one (12) with appropriate triethyl orthoesters or by oxidative cyclization