Benzo[c]cinnoline derivatives. I. Preparation and spectral characterization of N,N-dialkylaminobenzo[c]cinnolines

Abstract

Reactions of 1-, 2-, 3-, and-4-chlorobenzo[c]cinnoline with dialkylamines have yielded the four corresponding dimethylaminobenzo[c]cinnolines and 2-diethyl-aminobenzo[c]cinnoline. A compound formerly described in the literature as 2- diethylaminobenzo[c]cinnoline is clearly not the same compound as that now reported. The N.M.R. and ultraviolet-visible spectral characteristics of the new compounds provide ample confirmation of the respective molecular structures. A discussion of the possible structures of the first conjugate acids is presented, following comparisons of the ultraviolet-visible spectra of amino- and dialkylamino-benzo[c]cinnolines in dilute acid.