Preparation of pyrrolo[3,4-c]pyrroles
US4579949A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1983 |
| Grant date | Apr 1, 1986 |
| Priority date | — |
| Expiry date | May 11, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B57/004
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula ##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 reacting 1 mole of a disuccinate with 2 moles of a nitrile of the formula EQU R.sub.1 --CN (II) or EQU R.sub.2 --CN (III) or with 1 mole of a nitrile of the formula (II) and 1 mole of the nitrile of the formula (III), in an organic solvent and in the presence of a strong base at elevated temperature, and obtaining the compound of formula I from the reaction product by hydrolysis. The pyrrolo-[3,4-c]pyrroles are suitable for pigmenting organic material of high molecular weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.