One-pot Synthesis of Fused 2-Thiouracils: Pyrimidopyrimidines, Pyridopyrimidines and Imidazolopyrimidines

Abstract

Several 6-substitued-1-methyl-2, 5,7,8-tetrahydro-2-thiopyrimido[4,5-d]pyrimidine-4-ones and ethyl 7-amino-5-aryl-1-methyl-4-oxo-1,2,3,4-tetrahydro-2-thiopyrido[2,3-d]pyrimidines-6-carboxylates were synthesized by treatment of 6-amino-1-methyl-2-thiouracil with primary amines and formalin (40 %), and with ethyl 3-aryl-2-cyanoacrylate respectively. 8-Substituted-7-hydroxy-3-methyl-2-thioxanthines were synthesized by the treatment of 6-amino-1-methyl-5-nitroso-2-thiouracil with benzylidene-anilines. Elemental and spectral analyses were performed for the new compounds.

2-Amino-4,5-dihydrothiophene-3-carbonitriles: A New Synthesis, Quantum Chemical Studies, and Mannich-Type Reactions Leading to New Hexahydrothieno[2,3-d]pyrimidines

“…It should be noted that ADHTs 6 play here an unusual role of 1,3-dinucleophilic β-enaminonitrile species. In general, the Mannich-type reactions of β-enaminocarbonyls and related enamines with HCHO and primary amines leading to tetrahydropyrimidines are well known; − however, as far as we know, no cyclic enaminonitriles were reported as substrates in the Mannich reaction prior to our studies.…”

Facile construction of substituted pyrimido[4,5-d]pyrimidones by transformation of enaminouracil

“…The objective of the present work was to investigate the behavior of Mannich reaction towards 6-amino-1,3-dimethylpyrimidine-2,4(1 H ,3 H )-dione ( 1 ) as a bifunctional nucleophile with primary amines. Mannich reaction of 1 with primary aromatic or heterocyclic amines, namely, p -anisidine and m -nitroaniline, 2-aminothiazole, aromatic and heterocyclic aldehydes, namely; formaldehyde, piperonal, p -anisaldehyde as well as furfural in a molar ratio (1:1:2) gave pyrimido[4,5- d ]pyrimidine ring systems 2 – 5 via a double Mannich reaction ( Scheme 1 ), similar methods to obtain pyrimido[4,5- d ]pyrimidines have been reported [21–25] . Furthermore, involvement of both C-5 and 6-amino group in this reaction is in line with our reported work [10,26,27] and to Roth & Hagen work [28] .…”

A Novel One-Pot and Efficient Procedure for Synthesis of New Fused Uracil Derivatives for DNA Binding

“…In this work, it was in need to prepare first the unavailable starting material, 6-amino-1-[(2-chlorophenyl)methyl]-5-nitrosouracil (7). Reaction of 6-amino-1-[(2-chlorophenyl)methyl]uracil (6b) with aqueous sodium nitrite in the presence of acetic acid afforded a high yield of the coloured nitroso derivative 7[31]. Thus, reaction of 7 with different arylidene aniline in acetic acid took place by the elimination of aniline to give 8a-d.…”