Ringschlüsse an Chinonylmethanfarbstoffen und analogen Merocyaninen. 2. Mitteilung. Dihydronaphthophenazinone; Beeinflussung der Löslichkeitseigenschaften durch Substitution, Isolierung und Charakterisierung einer Zwischenstufe des Ringschlusses

Cyclization Reactions of Quinonylmethane Dyes and Analogous Merocyanines. 2. Communication: Dihydro‐oxo‐naphto‐phenazines. Correlation of Solubility and Substitution. Isolation and Characterization of an Intermediate Compound An intermediate compound of the cyclization reaction of 2‐chloro‐3‐(1‐cyclohexyl‐3‐methyl‐1,2‐dihydroquinoxalin‐2‐ylidenmethyl)‐naphthoquinone was isolated and characterized by spectroscopic methods. 6‐Chloro‐8‐cyclohexyl‐5,8‐dihydronaphtho[1,2‐ b ]phenazinone was obtained as the final product of this reaction. Several more dihydronaphtho[1,2‐ b ]phenazinone dyes were synthesized. The relationship of substitution and solubility of the dyes is discussed. The visible and 1 H‐NMR. and some mass spectra of the dyes are given.