peri-Naphthylenediamines. 33. Further studies of the reactions of 1,8-bis(dimethylamino)naphthalene with trifluoroacetic anhydride

The reaction of 1,8-bis(dimethylamino)naphthalene (1) (proton sponge) with a large excess of trifluoroacetic anhydride in the absence of a solvent afforded a complex mixture of products among which were trans- (2) and cis-diols (3) of the naphtho1,8-c,d]pyran series, the double proton sponge (4), its di- (5) and tetrafluoroacetyl (6) derivatives, and compound 7. These results differ substantially from those obtained previously in the reactions performed in various solvents. Some conversions of compounds 4 and 7 were investigated. The ¹⁹F NMR spectra of the compounds synthesized are discussed.