The linear and proximal benzo-separated derivatives of 8-phenyltheophylline, 1, 3-diethyl-8- phenylxanthine, 1, 3-dipropylxanthine, 1, 3-dibutylxanthine, 3-isobutyl-l-methylxanthine, theophylline, caffeine, and isocaffeine have been synthesized and evaluated for affinity at the A, and Az adenosine receptors. Although structure-activity relationships in the benzo- separated series differed from the relationships in the simple xanthines, the most potent of ...
