Process for desensitizing a 1-(alkylamino)alkyl-polysubstituted piperazinone during recovery
US4841053A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1988 |
| Grant date | Jun 20, 1989 |
| Priority date | — |
| Expiry date | Jan 21, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D241/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Certain polysubstituted piperazinones (PSP) having two or three methylene groups linking the N.sup.1 atom of the ring to the N atom of a terminal amine group, are found to be peculiarly prone to decomposition when subjected to elevated temperature after being contacted with water, and sensitive to the amount of base used in the base-induced ketoform reaction which generates the PSP represented by the structure ##STR1## These PSP are therefore produced by a modification of the ketoform reaction under essentially anhydrous conditions, using enough ketone to dissolve the PSP formed and a molar ratio of solid alkali metal hydroxide/diamine reactant in the range from at least 5 but less than 7. The PSP produced is recovered as a solution in the ketone, without contacting the PSP with water. The PSP product obtained after the ketone is distilled, is essentially pure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.