Pyrimidine derivatives and related compounds. Part 41. Reactions of 1,3,6-trimethyl-5-nitrouracil and its 6-bromomethyl analogue with amines and hydrazines. Synthesis of pyrazolo[4,3-d]pyrimidine N-oxides and their ring expansion to pyrimido[5,4-d]pyrimidines
作者:Kosaku Hirota、Yoshihiro Yamada、Tetsuji Asao、Shigeo Senda
DOI:10.1039/p19820000277
日期:——
pyrimidines. Treatment of compound (4) with primary amines afforded 2-substituted pyrazolo[4.3-d]pyrimidine 1-oxides (6a–I). Of these, compounds (6h–I) were converted into pyrimido[5,4-d]pyrimidines (11) by treatment with sodium ethoxide. Although treatment of compound (1) with hydrazines caused the known ring transformation giving pyrazolones (2a and b), a new type of denitration reaction was found
为了合成稠环嘧啶,已经研究了1,3,6-三甲基-5-硝基尿嘧啶(1)和6-溴甲基-1,3-二甲基-5-硝基尿嘧啶(4)与胺和肼的反应。用伯胺处理化合物(4),得到2-取代的吡唑并[4.3 - d ]嘧啶1-氧化物(6a–I)。其中,化合物(6h–I)转化为嘧啶基[5,4- d通过乙氧基钠处理]嘧啶(11)。尽管用肼处理化合物(1)导致了已知的环转化,得到吡唑啉酮(2a和b),但当化合物(4)与肼反应生成6--嗪基甲基-1,3-二甲基尿嘧啶(15a)时,发现了一种新型的脱硝反应和b)。用肼处理6-(取代的甲基)-1,3-二甲基-5-硝基尿嘧啶(13b-d)和(14)(由(4)制得)也得到(15a和b)。讨论了化合物(6),(11)和(15)的形成机理。