PHENAZINE (Azophenylene), C 12 H 8 N 2, in organic chemistry, the parent substance of many dyestuffs, e.g.
By the entrance of amino or hydroxyl groups into the molecule dyestuffs are formed.
OH N (CH 3) 2 (i 3), are extensively employed in the manufacture of the important dyestuffs known as the rhodamines.
Benzo-orthoxazines, -metoxazines and -paroxazines are known: dibenzoparoxazine or phenoxazine is the parent of a valuable series of dyestuffs; dibenzoparathiazine or thiodiphenylamine is important from the same aspect.
Benzo-ortho-diazines exist in two structural forms, cinnolin and phthalazine; benzo-meta-diazines are known as quinazolines; benzo-para-diazines are termed quinoxalines; the dibenzo-compounds are named phenazines, this last group including many valuable dyestuffs - indulines, safranines, &c. In addition to the types of compounds enumerated above we may also notice purin, tropine and the terpenes.