Neue,ungewöhnlich verlaufende Arylierungen der 1,5-Dihydroxy-4,8-diaminoanthrachinon-2,6-disulfonsäure mit Kresolen

A novel course of a phenylation reaction of 1,5-dihydroxy-4,8-diaminoanthraquin-one-2,6-disulfonic acid with cresols . The arylation of 1,5-dihydroxy-4,8-diaminoanthraquinone-2,6-disulfonic acid with m-cresol in conc. sulfuric acid gives in the presence of boric acid a mixture of monosulfonic acids which differ in the substitution of the m-cresol moiety. The main product ( 8 , 95%) is substituted at the p-position to the methyl group, the side product ( 12 , 5%) at the p-position to the OH group. The monosulfonic acid 8 , which could not be isolated is further sulfonated under the reaction conditions to the disulfonic acid 9 . In the case of o-cresol, the cresol moiety is substituted in the p-position ( 16 ) to OH group and in the case of p-cresol in the o-position ( 20 ) to OH group. The obtained monosulfonic acids 16 and 20 resp. are partially sulfonated further under the reaction conditions. The new structures are elucidated by ¹H- and ¹³C-NMR. spectroscopy and the pattern of arylation reaction with phenol is discussed.