Preparation of 1,4-diketopyrrolo-[3,4-c]pyrroles
US4613669A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1983 |
| Grant date | Sep 23, 1986 |
| Priority date | — |
| Expiry date | Jul 8, 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 aromatic or non-basic heterocyclic aromatic radical, which process comprises reacting 1 mole of the compound of formula ##STR2## wherein M is a metal atom, Z is alkyl or aryl, X is halogen or acetate, and m is a value from 0 to 2, with 1 mole of a compound of the formula EQU YCH.sub.2 COOZ (III) wherein Y is halogen, and with 1 mole of a nitrile of the formula EQU R.sub.1 --CN (IV) or R.sub.2 --CN (V) in an organic solvent and at elevated temperature, and isolating the compound of formula I. The compounds obtained according to the invention are suitable for pigmenting organic material of high molecular weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.