title: Facile construction of substituted pyrimido[4,5-d]pyrimidones by transformation of enaminouracil.
abstract: The reaction of 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (1) as a binucleophile with primary aromatic or heterocyclic amines and formaldehyde or aromatic (heterocyclic) aldehydes in a molar ratio (1:1:2) gave the pyrimido[4,5-d]pyrimidin-2,4-dione ring systems 2-5. Treatment of 1 with diamines and formalin in molar ratio (2:1:4) gave the bis-pyrimido[4,5-d]pyrimidin-2,4-diones 6-8. Furthermore, substituted pyrimido[4,5-d]pyrimidin-2,4-diones with uracil derivative 11 or spiro indole 16 were synthesized. Synthesis of pyrimido[4,5-d]pyrimidin-2,4-diones with different substitution at C-5 and C-7 was achieved to give 13 and 18, respectively.
authors: Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt.
authors: Wafaa S
authors: WS
authors: Hamama
authors: Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt.
authors: Mohamed A
authors: MA
authors: Ismail
authors: Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt.
authors: Hanaa A
authors: HA
authors: Al-Saman
authors: Department of Chemistry, Faculty of Science, Mansoura University, 35516 Mansoura, Egypt.
authors: Hanafi H
authors: HH
authors: Zoorob
keywords: Aldimine; Annulation; Double Mannich reaction; Ketimine; Uracil