4b acid 
CAS No. :88-44-8
Molecular formula : C7H9NO3S 
purposes : dye intermediates. 4B acid and 2,3-acid coupling can be obtained Pigment Red 6B, legislation cable music Baohong BK; With 2-naphthol coupling can be obtained paint Huangguangyangong BL. These pigments are widely used in inks, plastics, rubber, wire and cable, the Japanese products, such as a colorant.