7-Alkyl-1-methyladenines (12a, b) have been synthesized from 1-alkyl-4-aminomidazole-5-carboxamides (5a, b) in two steps [hence from adenine (1) in six steps]. The synthesis started with dehydration (using POCl3-HCONMe2) of 5a, b, readily obtainable from 1 in four steps according to previously reported procedures, and proceeded through cyclization between the resulting 4-(dimethylaminomethyleneamino)imidazole-5-carbonitrile derivatives (8a, b) and MeNH2. Similar cyclization between 1-benzyl-4-(ethoxymethyleneamino)imidazole-5-carbonitrile (11c) and MeNH2 yielded 7-benzyl-1-methyladenine (12c).
7-烷基-
1-甲基腺嘌呤 (12a, b) 由 1-烷基-
4-氨基咪唑-5-甲酰胺 (5a, b) 分两步合成 [因此由
腺嘌呤 (1) 分六步合成]。合成从 5a、b 的脱
水(使用 POCl3-HCONMe2)开始,根据先前报道的程序,可以通过四个步骤从 1 中轻松获得,然后通过所得 4-(二甲基
氨基亚甲基
氨基)
咪唑-5-甲腈衍
生物(8a, b) 和MeNH2。 1-苄基-4-(乙氧基亚甲基
氨基)
咪唑-5-甲腈(11c)和MeNH2之间类似的环化产生7-苄基-
1-甲基腺嘌呤(12c)。