The more complex phenazines, such as the naphthophenazines, naphthazines and naphthotolazines, may be prepared by condensing ortho-diamines with ortho-quinones (0.
If alkyl or aryl-ortho-diamines be used azonium bases are obtained.
P. Griess (Ber., 1872, 5, p. 192; 18 74, 7, p. 1223) orientated the three diaminobenzenes or phenylene diamines by considering their preparation by the elimination of the carboxyl group in the six diaminobenzoic acids.
It combines with ortho-diamines, in the presence of acetic acid, to form phenazines.
Diamines.-The diamines contain two amino groups and bear the same relation to the glycols that the primary monamines bear to the primary alcohols.