2-Aminonaphthalene-7-sulfonic acid

2-Aminonaphthalene-7-sulfonic acid [494- 44-0].  (7-aminonaphthalene-2-sulfonic acid), amido F acid, C10H9NO3S, Mr 223.24, crystallizes as the monohydrate in needles or prisms although only 0.3 % soluble at 100℃. Bromination gives the 1-bromo derivative, caustic fusion results in 7-amino-2-naphthol, and sulfonation with oleum gives a mixture of disulfonic acids.

2-Hydroxynaphthalene-7-sulfonic acid is aminated by a Bucherer reaction under conditions similar to those used for Tobias acid.