Synthese und spektrale Charakterisierung von blauen Benzenazofarbstoffen

Synthesis and Spectral Characterization of Blue Azo Dyes of the Benzene Series 53 Donor‐acceptor substituted azo dyes of the benzene series were prepared by diazonium‐coupling reactions ( 1 a–s ) or halogen‐cyanide exchange (→ 2 a–x, 3 a–j ). Described are the preparation of the amines 4 a–m and the coupling compounds 5 a–t and the procedure of diazotizing and coupling. The colouristic and spectroscopic data show that compounds of the general formula 1 are excellent brilliant blue azo dyes useful for dyeing polyester material.