SYNTHESIS OF PYRIMIDINE-ANNELATED HETEROCYCLES: THERMAL REARRANGEMENT OF 1,3-DIMETHYL-5-(PROP-2-ENYLTHIO)-PYRIMIDINE-2,4-DIONES
作者:K. C. Majumdar、N. K. Jana、A. Bandyopadhyay、S. K. Ghosh
DOI:10.1081/scc-100105669
日期:2001.1
Thermal [3,3] sigmatropic rearrangement of a number of 1,3-dimethyl-5-(prop-2-enylthio)uracils (3a–c) afforded pyrimidine-annelated heterocycles in 65–80% yields. While 3a and 3b gave 1,3-dimethyl-tetrahydropyrano[3,2-d]pyrimidine-2,4-dione (4a) and 1,3,6-trimethyl thieno[3,2-d]pyrimidine-2,4-dione (6b), 3c furnished 6,7-dihydro-1,3,6-trialkyl thieno[3,2-d]pyrimidine-2,4-dione (5c) and 3d gave 1,3
许多 1,3-二甲基-5-(丙-2-烯基硫代)尿嘧啶 (3a-c) 的热 [3,3] σ 重排以 65-80% 的产率提供了嘧啶环化杂环。而3a和3b得到1,3-二甲基-四氢吡喃[3,2-d]嘧啶-2,4-二酮(4a)和1,3,6-三甲基噻吩并[3,2-d]嘧啶-2,4 -二酮 (6b),3c 提供 6,7-二氢-1,3,6-三烷基噻吩并[3,2-d]嘧啶-2,4-二酮 (5c) 和 3d 得到 1,3-二甲基-5- mercapto-6-(3-methylbut-2-enyl)pyrimidine-2,4-dione (8d)。产物5c随后在二苯醚中用钯炭脱氢得到1,3-二烷基-6-乙基噻吩并[3,2-d]嘧啶-2,4-二酮(6c)。