3289-53-0Relevant articles and documents
Tunable Push-Pull Interactions in 5-Nitrosopyrimidines
Procházková, Eli?ka,?echová, Lucie,Tarábek, Ján,Janeba, Zlatko,Dra?ínsky, Martin
, p. 3780 - 3789 (2016/06/06)
The effect of push-pull interactions in a series of variously substituted 5-nitrosopyrimidines on the strength of intramolecular hydrogen bonds, the height of rotational barriers around formally single bonds, UV-vis spectra and electrochemical behavior is explored. Intramolecular charge transfer (ICT) leads to a shift of electron density from electron-donating substituents, which is readily observable by NMR spectroscopy. The 5-nitroso group is able to form strong intramolecular hydrogen bonds with neighboring amino substituents. As a result, two rotamers with reversed orientation of the 5-nitroso group are observed for compounds with two different hydrogen-bond donors in neighboring positions. The barriers of interconversion between the two rotamers are strongly influenced by ICT, whereas the ratio of such rotamers depends primarily on the character of the hydrogen-bond donors. The ICT also significantly affects the position of UV-vis absorption maxima, which can be tuned in a broad range of 100 nm by the selection of appropriate substituents. Finally, ICT influences oxidation potential of the 5-nitrosopyrimidines and the stability of the resulting nitroso radical cations, the structures of which are determined by EPR spectroscopy.
Derivatives of 4-amino-6-hydroxy-2-mercaptopyrimidine as novel, potent, and selective A3 adenosine receptor antagonists
Cosimelli, Barbara,Greco, Giovanni,Ehlardo, Marina,Novellino, Ettore,Da Settimo, Federico,Taliani, Sabrina,La Motta, Concettina,Bellandi, Marusca,Tuccinardi, Tiziano,Martinelli, Adriano,Ciampi, Osele,Trincavelli, Maria Letizia,Martini, Claudia
, p. 1764 - 1770 (2008/12/22)
A number of derivatives of 4-amino-6-hydroxy-2-mercaptopyrimidine (5) were synthesized and biologically evaluated as A3 adenosine receptor (A3 AR) antagonists. The new compounds were designed as open chain analogues of a triazolopyrimidinone derivative displaying submicromolar affinity for the A3 AR, which had been previously identified using a 3D database search. Substituents R, R′, and R″ attached to the parent compound 5 were chosen according to factorial design and stepwise lead optimization approaches, taking into account the essentially hydrophobic nature of the A3 AR binding site. As a result, 5m (R = n-C3H 7, R′ = 4-ClC6H4CH2, R″ = CH3) was identified among the pyrimidine derivatives as the ligand featuring the best combination of potency and selectivity for the target receptor. This compound binds to the A3 AR with a Ki of 3.5 nM and is devoid of appreciable affinity for the A1, A 2A, and A2B ARs.
Novel procedure for selective C-nitrosation of aminopyrimidine derivatives under neutral conditions. Scope and synthetic applications
Marchal, Antonio,Melguizo, Manuel,Nogueras, Manuel,Sánchez, Adolfo,Low, John N.
, p. 255 - 258 (2007/10/03)
A novel simple method, based on treatment with isoamyl nitrite (IAN) in DMSO without any added acid, to produce selective C(5)-nitrosation of aminopyrimidine derivatives is described. It proved to be suitable for a multigram scale and applicable to a larger range of pyrimidine derivatives, including amino-dialkoxypyrimidines, than the procedures previously known. Its scope is analyzed and some example on the usefulness of the newly prepared substances as intermediates in the synthesis of fused heterobicyclic derivatives of potential biological interest is presented.
Synthesis of the caffeine metabolites 5-acetylamino-6-formylamino-3-methyluracil (AFMU) and 5-acetylamino-6-amino-3-methyluracil (AAMU) on a preparative scale
Roehrkasten,Raatz,Kreher,Blaszkewicz
, p. 1526 - 1532 (2007/10/03)
5-Acetylamino-6-amino-3-methyluracil (AAMU) and 5-acetylamino-6-formylamino-3-methyluracil (AFMU) have been prepared by simple chemical transformations starting from thiourea and ethyl cyanoacetate. These compounds AAMU and AFMU are required as standard m
