Preparation of piperazinones for use as sulfur dioxide absorbents
US4980471A · kind A · utility
4Cited by
8References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1989 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Oct 6, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D241/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The 2-piperazinones are made by reacting a 1-cyano-1-hydroxyalkane with ethylenediamine or a substituted ethylenediamine in aqueous solution. The process to make the 2-piperazinones suitable as a regenerable sulfur dioxide absorbing medium requires that the cyano compound be present in at least a molar equivalent amount to the diamine and that the resulting 2-piperazinone product be sparged with an inert gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.