114811-73-3Relevant academic research and scientific papers
Aza-analogs of 8-styrylxanthines as A(2A)-adenosine receptor antagonists
Mueller, Christa E.,Sauer, Roland,Geis, Uli,Frobenius, Wolfram,Talik, Przemyslaw,Pawlowski, Muciej
, p. 181 - 189 (2007/10/03)
In the present study we synthesized aza-analogs of 8-styrylxanthines, in which the ethenyl bridge is replaced by an imine, amide, or azo function, in order to investigate structure-activity relationships of the 8-substituent of A(2A)-selective xanthine derivatives. Thus, various 8-substituents were combined with theophylline or caffeine, respectively, and affinities of the novel compounds for adenosine A1- and A(2A)-receptors were determined and compared with those of analogous 8-styrylxanthine derivatives. 8-(Benzylideneamino)caffeine derivatives exhibited high affinity and selectivity for A(2A)-adenosine receptors, but were unstable in aqueous buffer solution at physiological pH values. 8-(Phenylazo)caffeine derivatives were less potent than corresponding 8-styrylcaffeine derivatives at adenosine receptors. The most potent azo compound of the present series was 8-(m-chlorophenylazo)caffeine (14b) exhibiting a K(i) value of 400 nM at A(2A)-adenosine receptors and 20-fold selectivity versus A1-receptors. Due to the facile synthetic access to 8-(phenylazo)xanthine derivatives, which are obtained by coupling of 8-unsubstituted xanthines with phenyldiazonium salts, 14b may be an interesting new lead compound for the development of more potent and selective A(2A)-antagonists with azo structure.
PURINES, PYRIMIDINES, AND CONDENSED SYSTEMS BASED ON THEM. 3.7,8-DIAMINOTHEOPHYLLINE
Nanavyan, I. M.,Kuz'menko, V. V.,Pozharskii, A. F.,Klyuev, N. A.
, p. 1123 - 1129 (2007/10/02)
By treating 8-aminotheophylline with hydroxylamine-O-sulfonic acid in aqueous alkali we have obtained 7,8-diaminotheophylline and studied its reactions with benzaldehyde, 1,2-dicarbonyl compounds, and acylating agents.We have established that in reactions with electrophiles, the N-amino group in 7,8-diaminotheophylline is more active than the amino group situated at the 8-position.An unexpected self-condensation of two molecules of 7,8-diaminotheophylline has been found in acid medium, leading to purino-7-azapteridine derivatives.
