Purines. LX. Dimroth Rearrangement and Concomitant Hydrolytic Deamination of 7-Alkyl-1-methyladenines.
作者:Tozo FUJII、Tohru SAITO、Ryoko II、Tomoko SUZUKI
DOI:10.1248/cpb.42.382
日期:——
The Dimroth rearrangement of 7-alkyl-1-methyladenines (8) to produce 7-alkyl-N6-methyladenines (9) (63-72% yield) has been found to be accompanied with unusual hydrolytic deaminations to give 7-alkyl-1-methylhypoxanthines (10) (1-3.5%) and/or 7-alkylhypoxanthines (11) (12-22%), when effected in boiling H2O for 4-70 h. Probable pathways leading to these by-products are proposed.
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)。