Unusual Double ‘O/N to N/O’ Recyclization of 5-Alkyl-7,8-dimethoxy-2arylbenzo[d]pyrrolo[3,2-b]pyrylium Perchlorates into 5-Alkyl-7,8dimethoxy-2-arylfuro[2,3-c]isoquinolines

Novel unusual double recyclization of both pyrrole and pyrylium cores of 5alkyl-7,8-dimethoxy-2-phenylbenzo[d]pyrrolo[3,2-b]pyrylium perchlorate by nucleophiles is described, which regardless of the nucleophile (ammonium carbamate, triethylamine, sodium acetate, HCl in methanol), results in 5-alkyl-7,8-dimethoxy-2-phenylfuro[2,3-c]isoquinoline. The structure of 5-methyl-7,8-dimethoxy-2-phenylfuro[2,3-c]isoquinoline was established from X-ray diffraction analysis.