Reaction of purine and 2-methyl- and 8-methylpurine with potassium amide in liquid ammonia leads to the formation of adenine and 2-methyl- and 8-methyladenine, respectively. 6-Methyl- and 6,8-di-tert-butylpurine do not react. It was proven by applying 15N-labeled potassium amide that the amination reactions do not involve opening of the pyrimidine ring. Low temperature NMR spectroscopy showed that in solutions of purine and 2-methylpurine in potassium amide-liquid ammonia an anionic σ complex at position 6 is formed. 8-Methylpurine on the contrary only showed the presence of a monoanion and a dianion.
|Journal||Journal of Organic Chemistry|
|Publication status||Published - 1979|