Synthesis of 2-tetrazolylmethyl-tetrahydro-1H-beta-carboline methane-linked bis-heterocycles via one pot Ugi-azide / Pictet-Spengler process

A series of seven new 2-tetrazolylmethyl-tetrahydro-1H-beta-carboline methane-linked bis-heterocycles including their fluorine-containing analogs were synthesized in good to excellent yields (74-97%) via one pot Ugi-azide / Pictet-Spengler strategy under mild thermal conditions. One intermediate (Ugi-azide product) was isolated and fully characterized in order to confirm the reaction pathway. The products herein described may find application in medicinal chemistry because they are formed by two heterocyclic frameworks (1,5-disubstituted-1H-tetrazole and tetrahydro-beta-carboline), which are present in a variety of bioactive compounds and drugs. In the same context, it has been reported that fluorine atoms placed suitably into structures of bioactive compounds enhances often very interesting features like bioavailability, lipophilicity and metabolic resistance.