New heterocyclic systems. Benzo[4,5]cyclohepta[1,2-b]pyrrole and benzo[5,6]cyclohepta[1,2-f]pyrrolizidine derivatives

The synthesis of the polycyclic pyrrole acetic acids 9e, 13e and 13g by multistep processes from 1-bromo-4-phenylbutan-2-one ( 6c ) is reported. An instance of the use of the 2-chloroethyl moiety as a pyrrole nitrogen protecting group is described. The α-methylaminoketone ( 6e ) was synthesised by a novel two step process from 6c and methyl N-methylformimidate ( 12 ).