Direct preparation of pyrrolo[3,4-C]pyrroles
US6361594B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 14, 2000 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Feb 14, 2020 |
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) wherein each of R1 and R2 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)R1—CN  (II)or of the formula (III)R2—CN  (III)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.