synthesis and reactivity of [1,2,4]triazolo-annelated quinazolines的合成和反应(1、2、4)triazolo-annelated喹唑啉.pdfVIP

Molecules 2010, 15, 7016-7034; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis and Reactivity of [1,2,4]Triazolo-annelated Quinazolines Rashad A. Al-Salahi Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia; E-Mail: salahi76@ Received: 25 September 2010; in revised form: 29 September 2010 / Accepted: 8 October 2010 / Published: 12 October 2010 Abstract: This paper reports the synthesis of phenyl-substituted 2-alkoxy(methylsulfanyl)- 1,2,4-triazolo[1,5-a]quinazolines starting from N-cyanoimidocarbonates and substituted hydrazinobenzoic acids as building blocks. Thionation or chlorination of the inherent lactam moiety in the target compounds followed by treatment with multifunctional nucleophiles provided access to a variety of derivatives. Keywords: triazolo[1,5-a]quinazolines; thionation; alkylation; chlorination; tetracyclic systems 1. Introduction Triazolo-annelated quinazolines are known to constitute a pharmacologically interesting class of compounds. For instance, the novel compound Ia is effective adenosine antagonist whereas the related compound Ib was found to be benzodiazepine receptor antagonist [1-3]. The recently reported 1,2,4- triazoloquinazolines of type II were also found to exhibit promising antihistaminic activity against histamine induced bronchospasms and showed neglig