A Convenient Synthesis of Spiroindolo[2,1-b]quinazoline-6,2′-[1,3,4]oxadiazoles from Tryptanthrin and Nitrile Imines

Development of heterocyclic synthesis has always been an important area in synthetic organic chemistry. Spiro heterocycles are regarded as a privileged framework because of their rigidity, three-dimensional geometries, and wide distribution in various natural products and synthetic molecules. Currently, these spirans are attracting considerable interest in organic chemistry because of their molecular structure and diverse biological activities.1 In particular, spiroindoles represent important structural motifs that can be found in many biologically active synthetic compounds and natural products.2,3 Herein, we report the synthesis of new 5′-aryl-3′-phenyl-3′H,12H-spiro[indolo[2,1-b]quinazoline-6,2′-[1,3,4]oxadiazol]-12-ones 3 from the reaction between tryptanthrins 1 and hydrazonoyl chlorides 2 in MeCN at 80 in the presence of Et3N (Figure 1).4 All synthesized compounds are stable solids whose structures were determined on the basis of their mass spectrum, 1H and 13C NMR and IR spectroscopic data.

کلیدواژه ها:

Spirocompound ، 1 ، 3-Dipolar cycloaddition ، Tryptanthrin ، 1 ، 3 ، 4-Oxadiazole.