Direct preparation of pyrrolo[3,4-c]pyrroles
US6057449A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 13, 1999 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | May 13, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0033
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process is disclosed for the direct preparation of pigmentary 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula (I) ##STR1## wherein each of R.sub.1 and R.sub.2 independently of the other is an isocyclic or heterocyclic aromatic radical, which process comprises heating an appropriate molar ratio of a disuccinate with a nitrile of the formula (II) ##STR2## or of the formula (III) ##STR3## or with mixtures of said nitrites, in an organic solvent and in the presence of a strong base and an effective amount of a selected particle growth inhibitor of formula (IV)-(X), and then obtaining the compound of formula (I) from the reaction product by protolysis. The process yields pigmentary 1,4-diketopyrrolo-[3,4-c]pyrroles directly, i.e., without the need for additional particle-size reducing aftertreatments. Also disclosed is a composition comprising a pigmentary 1,4-diketopyrrolo-[3,4-c]pyrrole and the particle growth inhibitor. These pigment compositions are useful for pigmenting high molecular weight organic materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.