Patent ID: 6566519
Filing Date: 2003-05-20
Classification: B01J,C09B,F28F,Y10T

Abstract:
A process for preparing 1,4 diketopyrrolo[3,4-c]pyrrole pigments of the formula (I) where R1 and R2 are identical or different and are each an unsubstituted or substituted isocyclic or heterocyclic aromatic radical, by reaction of a succinic diester with a nitrile of the formula (II)R1â€”CNâ€ƒâ€ƒ(II) or of the formula (III)R2â€”CNâ€ƒâ€ƒ(III) or with a mixture of these nitriles, in an organic solvent and in the presence of a strong base, and subsequent hydrolysis of the resultant salt of the diketopyrrolopyrrole pigment, which comprising conducting the reaction, or the hydrolysis, or the reaction and the hydrolysis, in a microreactor having clear width channel dimensions between about 10 &mgr;m and about 800 &mgr;m.