Reductive cyclization of ω-azido/nitrocarbonyl compounds by samarium iodide:: a facile preparation of DNA-binding pyrrolo[2,1-c][1,4]benzodiazepine and its dimers

An efficient synthesis of pyrrolo[2,1-c][1,4]benzodiazepines via reductive cyclization of omega -azido/nitrocarbonyl compounds employing samarium iodide is described. This methodology has also been extended for the preparation of DNA-crosslinking DC-81 dimers. (C) 2000 Elsevier Science Ltd. All rights reserved.