Xanthene dyes having a fused (C) benzo ring

A compound of the formula:

• ##STR7## wherein:
• R.sup.1 is hydrogen, acetyl or methyl,
• R.sup.2 is N,N-dialkylamine, of which each alkyl group consists of 3 methylene groups which, in conjunction with R.sup.3 and R.sup.4, complete two six-membered non-aromatic rings chemically bonded to the aromatic ring of benzo[c]xanthene, and
• R.sup.5 and R.sup.6, which may be the same or different, are hydrogen, carboxyl or acetoxymethoxycarbonyl.

A compound of the formula:

• ##STR8## wherein:
• R.sup.1 is hydrogen, a metal or non-metal salt, an alkyl or aryl ether containing from 1 to 18 carbon atoms, or an ester of an aliphatic acid containing from 1 to 18 carbon atoms;
• R.sup.2 is hydroxyl, amino, or an amino modified by formation of an alkylether, alkylester, alkylamide or alkylamine derivative containing 1 to 18 carbon atoms;
• R.sup.5 and R.sup.6, which may be the same or different, are carboxy, sulfo, or alkylamido containing 1 to 6 carbon atoms;
• and
• R.sup.3, R.sup.4, R.sup.7 and R.sup.8, which may be the same or different, are alkoxyl containing from 1 to 6 carbon atoms, alkyl containing from 1 to 6 carbon atoms, haloalkyl containing from 1 to 6 carbon atoms, or halo.