A detailed account is given of the first unequivocal synthesis of adenine 7-oxide (8). The synthesis started with peroxycarboxylic acid oxidation of 3-benzyladenine (6), readily obtainable from adenine (1) by benzylation, and proceeded through nonreductive debenzylation of the resulting 3-benzyladenine 7-oxide (7). The location of the oxygen function in 7 and 8 was confirmed by their chemical reactions including deamination and methylation and by X-ray crystallographic analysis. A UV spectroscopic approach suggested that the neutral species of 8 exists in H2O as an equilibrated mixture of the N(7)-oxide (8) and N(7)-OH (21) tautomers. Treatment of 6 with 30% aqueous H2O2 in MeOH in the presence of MeCN and KHCO3 at 30°C produced the N(7)-oxide 7 and 7-acetamido-3-benzyladenine (15) in 12% and 1% yields, respectively.
详细报道了首次明确的
腺嘌呤7-氧化物(8)合成过程。该合成从
3-苄基腺嘌呤(6)的过氧
羧酸氧化开始,6可由
腺嘌呤(1)苄基化得到,接着通过非还原性去苄基化得到产物
3-苄基腺嘌呤7-氧化物(7)。7和8中氧官能团的位置通过
化学反应(包括脱
氨和甲基化反应)和X射线晶体学分析得到证实。紫外光谱学方法表明,中性物种8在
水溶液中以N(7)-氧化物(8)和N(7)-羟基(21)互变平衡混合物的形式存在。在
乙腈和
碳酸氢钾存在下,将6与30%的
过氧化氢水溶液在
甲醇中30°C反应,得到N(7)-氧化物7和7-乙酰胺基-
3-苄基腺嘌呤(15),产率分别为12%和1%。