2‐Amino[1,2,4]triazolo[1,5‐c]quinazolines and Derived Novel Heterocycles: Syntheses and Structure–Activity Relationships of Potent Adenosine Receptor Antagonists |
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Authors: | Dr Joachim C Burbiel Dr Wadih Ghattas Dr Petra Küppers Dr Meryem Köse Dr Svenja Lacher Dr Anna‐Maria Herzner Dr Rajan Subramanian Kombu Prof?Dr Raghuram Rao Akkinepally Dr Jörg Hockemeyer Prof?Dr Christa E Müller |
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Affiliation: | 1. Pharmazeutische Chemie I, Universit?t Bonn, Pharma-Zentrum Bonn, Pharmazeutisches Institut, Bonn, Germany;2. University College of Pharmaceutical Sciences, Kakatiya University, Warangal, India;3. (+49)?228‐73‐2567 |
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Abstract: | 2‐Amino1,2,4]triazolo1,5‐c]quinazolines were identified as potent adenosine receptor (AR) antagonists. Synthetic strategies were devised to gain access to a broad range of derivatives including novel polyheterocyclic compounds. Potent and selective A3AR antagonists were discovered, including 3,5‐diphenyl1,2,4]triazolo4,3‐c]quinazoline ( 17 , Ki human A3AR 1.16 nm ) and 5′‐phenyl‐1,2‐dihydro‐3′H‐spiroindole‐3,2′‐1,2,4]triazolo1,5‐c]quinazolin]‐2‐one ( 20 , Ki human A3AR 6.94 nm ). In addition, multitarget antagonists were obtained, such as the dual A1/A3 antagonist 2,5‐diphenyl1,2,4]triazolo1,5‐c]quinazoline ( 13 b , Ki human A1AR 51.6 nm , human A3AR 11.1 nm ), and the balanced pan‐AR antagonists 5‐(2‐thienyl)1,2,4]triazolo1,5‐c]quinazolin‐2‐amine ( 11 c , Ki human A1AR 131 nm , A2AAR 32.7 nm , A2BAR 150 nm , A3AR 47.5 nm ) and 9‐bromo‐5‐phenyl1,2,4]triazolo1,5‐c]quinazolin‐2‐amine ( 11 q , Ki human A1AR 67.7 nm , A2AAR 13.6 nm , A2BAR 75.0 nm , A3AR 703 nm ). In many cases, significantly different affinities for human and rat receptors were observed, which emphasizes the need for caution in extrapolating conclusions between different species. |
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Keywords: | A3 adenosine receptor antagonists iminoquinazolinamines microwave-assisted synthesis species differences |
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