Base-promoted transformation of 2-C(O)R-1,8-bis(dimethylamino)naphthalenes into benzo[g]indole derivatives

1,8-Bis(dimethylamino)naphthalenes bearing 2-positioned trifluoroacetyl or ethoxycarbonyl group on treatment with 2-lithio-1,8-bis-dimethylamino)naphthalene undergo base-promoted transformation into benzo[ g ]indole derivatives in small to moderate yield, representing previously unknown mode of the pyrrole ring closure which proceeds via deprotonation of the NMe group.