1. Alves MJ, Booth BL, Freitas AP, Proenca MF (1992) (Z)-N3-(2-Amino-1,2-dicyanovinyl)formamidrazone: a precursor in the synthesis of 1,5-diaminoimidazoles and 6-carbamoyl-1, 2-dihydropurines. J Chem Soc Perkin Trans 1:913–917
2. Alves MJ, Booth BL, Proenca MFP (1987) Some reactions of 5-amino-4-(C-cyanoformimidoyl) imidazoles obtained from nitrilium trifluoromethane sulphonate salts and diaminomaleonitrile. J Chem Soc Perkin Trans 1:1521–1526
3. Alves MJ, Booth BL, Proenca MF (1994) Synthesis of 4- and 5-disubstituted 1-benzylimidazoles, important precursors of purine analogs. J Heterocycl Chem 31:345–351
4. Yahyazadeh A, Pourrostam B (2003) Synthesis of 9-benzyl-6-aminopurines from 5-amino-1-benzyl-4-cyanoimidazoles. Bull Korean Chem Soc 24:1723–1724
5. Booth BL, Alves MJ, Carvalho A, Eastwood PR, Nezhat L (1994) Synthesis of 9-aryl-6-carbamoyl-1,2-dihydropurines and a study of their tautomerism. J Chem Soc Perkin Trans 2:1949–1956