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-substituted derivatives (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
本文描述了噻吩并[2,3-e]-[1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one (5a) 及其 2-取代衍生物的可靠通用合成方法(5b-i) 作为一种新的环系统,通过其 [4,3-c] 化合物 (4a-i) 的灵活异构化制备,这些化合物由 4-肼基噻吩-[3,2-d]嘧啶-2 缩合产生(1H)-one (12) 与适当的原三乙酯或通过 4-(亚苄基肼基)噻吩并[3,2-d]pyrimidin-2(1H)-ones (13c-i) 的氧化环化。[1,5-c] 异构体 (5a-c) 进一步通过缩合 3-amino-4-imino-2-oxo-1,2,3,4-tetrahydrothieno[3,2-d] 嘧啶 ( 16)用适当的原三乙酯作为三环系统结构可靠的合成方法。