Patent ID: 7638609

Claim:
A compound of Formula (1) or salt thereof: wherein: A is phenyl carrying one to three substituents selected from carboxy, sulpho, phosphato, amino, optionally substituted C 1-6 alkyl, optionally substituted C 1-6 alkoxy, acetamido, nitro and N-oxamoyl; B is phenylene or naphthylene carrying one or two substituents selected from sulpho, methyl, methoxy, acetamido, amino and 2-hydroxethoxy; n is 0 or 1; and D is of Formula (3a), (3b) or (3c); wherein R 2 and R 5 are each independently H, carboxy, cyano or optionally substituted alkyl, alkoxy, acyl, aryl, amino, amido, carbonamido, carboxyester, sulphamoyl or alkylsulphonyl; and R 3 and R 4 are each independently H or optionally substituted aryl or alkyl; and * shows the point of attachment to the azo linkage in Formula (1).