Reactions of bis(tetrazole)phenylenes. Surprising formation of vinyl compounds from alkyl halides

Reactions of either 1,n-(HN4C)2C6H4 or 1,n-(Bu3SnN4C)2C6H4 (n=2, 3, 4) with 1,2-dibromoethane yields compounds containing pendant bromoethyl or vinyl groups with substitution occurring at either 1-N,2-N′ or 2-N,2-N′, respectively.