Unexpected ring closures leading to 2- N , N -dialkylaminoareno[1,3]tellurazoles

A novel synthetic method has been developed to prepare 2- N , N -areno[1,3]tellurazoles following a one step procedure from readily accessible precursors. Products were obtained in yields up to 78% by reacting bis(2-aminoaryl)ditellurides with dialkylformamides in the presence of phosphorous trichloride or phosphorous oxychloride. An analogous approach furnished 2-( N , N -dimethylamino)naphtho[1,2- d ][1,3]tellurazole from 3-chloronaphtho[2,1- c ]-1,2,5-oxatellurazole. This method was found to be specific to the synthesis of 2-dialkylaminotellurazoles and does not proceed with sulfur or selenium congeners. A characterization of two selected samples by X-ray crystallography found a supramolecular wire motif resulting from intermolecular Te⋯N interactions for one of them.