Acetic acid, tris(formylmethylamino)-, 2,4-bis[[4-[(2-thiazolylamino)sulfonyl]phenyl]azo]-5-[[tris(formylmethylamino)acetyl]amino]-1-naphthalenyl ester, compd. with 4,4'-[[4-(methylamino)phenyl]methylene]bis(N,N-dimethylbenzenamine) monohydrochloride (1:1) Acetic acid, tris(formylmethylamino)-, 2,4-bis[[4-[(2-thiazolylamino)sulfonyl]phenyl]azo]-5-[[tris(formylmethylamino)acetyl]amino]-1-naphthalenyl ester, compd. with 4,4'-[[4-(methylamino)phenyl]methylene]bis[N,N-dimethylbenzenamine] monohydrochloride (1:1) NSC337383