1: 6-[(2,2-diphenylethyl)amino]-9H-purine-2-carboxylic acid With 1,1'-carbonyldiimidazole in DMF (N,N-dimethyl-formamide) T=20°C; 5 h; 2: 2-(1-piperidyl) ethylamine T=20°C; 20 h; Product distribution / selectivity;