Synonyms: 2',4'-Acetoacetoxylidide,2,2''-[(2,2',5,5'-tetrachloro-4,4'-biphenylylene)bis(azo)]bis- (6CI,8CI);Butanamide,2,2'-[(2,2',5,5'-tetrachloro[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[N-(2,4-dimethylphenyl)-3-oxo-(9CI);C.I. 21127;C.I. Pigment Yellow 81;KET Yellow 401;Lithol Fast Yellow 0991K;Novoperm Yellow H 10G;Novoperm Yellow H 10G01;PV Yellow H 10G;PermanentYellow H 10G;