Tetraphenylketazines and isoindolinone pigments obtained therefrom

An isoindolinone pigment of the formula ##STR35## wherein X.sub.1, X.sub.2, X.sub.3 and X.sub.4 represent hydrogen or halogen atoms, or one or two of X.sub.1 -X.sub.4 represent alkoxy groups of 1 to 4 carbon atoms or phenoxy groups and the others represent hydrogen or halogen atoms, R and R" represent hydrogen or halogen atoms or methyl or methoxy groups, R.sub.1, R.sub.2, R.sub.4 and R.sub.5 represent hydrogen, chlorine or bromine atoms or alkyl groups of 1 to 2 carbon atoms, R.sub.3 and R.sub.6 represent hydrogen or halogen atoms, alkyl or alkoxy groups of 1 to 2 carbon atoms or when R.sub.3 and R.sub.6 are independently in the meta or para position in respect to X, R.sub.3 and R.sub.6 may also be a group of the formula ##STR36## Q represents a direct bond or a p-phenylene groups, n is 1 or 2 and X represents a group of the formula ##STR37## wherein R.sub.7 and R.sub.8 represent hydrogen or chlorine atoms or methyl groups.