The 2-deuterated species XI-XIII of 3, 9-dimethyladenine salts (Ia, b) and of 3-benzyl-9-methyladenine perchlorate (Ie) have been synthesized from the alkylaminoimidazoles VII and VIII through deuterioformylation with formic-d acid-d, hydrogenolytic demethoxylation, adn amidine-formamido cyclization. Comparison of the proton nuclear magnetic resonance spectra of XI-XIII with those of the isotophically unmodified species Ia, b, e permitted a distinction between C(2)-and C(8)-proton signals observed for a series of 3, 9-dialkyladenine salts (Ia-I) : the C(2)-proton resonates at lower field than does the C(8)-proton by 0.04-0.52 ppm. The low electron density at C(2) of I was also exemplified by the NaBH4 reduction of 3, 9-dimethyladenine perchlorate (Ib) to give the 1, 2-dihydro derivatibe XIX. The structrue of XIX was confirmed by a similar reduction of the 2-deuterated species XII, leading to XX.
2-
氘化物种XI-XIII的3,9-二甲基
腺嘌呤盐(Ia, b)和3-苄基-
9-甲基腺嘌呤过
氯酸盐(Ie)是通过与
氘代
甲酸(formic-d acid-d)的
氘代甲酰化反应,以及氢解去甲氧基化和
胍基-
氨基甲酰化环化反应,从烷基
氨基
咪唑(VII和VIII)合成的。将XI-XIII的质子核磁共振谱与未同位素修饰的种类Ia, b, e进行比较,可以区分在一系列3,9-二烷基
腺嘌呤盐(Ia-I)中观察到的C(2)和C(8)质子信号:C(2)质子的共振频率在0.04-0.52 ppm范围内低于C(8)质子。同时,I的C(2)位点的低电子密度也通过对3,9-二甲基
腺嘌呤过
氯酸盐(Ib)的NaBH4还原反应得到体现,生成了1,2-二氢衍
生物XIX。XIX的结构通过对2-
氘化物种XII进行类似的还原反应确认,得到了XX。