Method for the preparation of piperazine and its derivatives
US6603003B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2001 |
| Grant date | Aug 5, 2003 |
| Priority date | — |
| Expiry date | Oct 25, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D471/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A novel method for the synthesis of piperazine and its derivatives of formula 1, wherein R is selected from hydrogen, or a lower alkyl group having 1 to 6 carbon atoms or a phenylalkyl group the alkyl of which has 1 to 4 carbon atoms;R1 is selected from hydrogen, a methyl group, a phenyl group optionally substituted with an alkyl group having 1 to 6 carbon atoms, or a phenylalkyl group the alkyl of which has 1 to 4 carbon atoms; andR2 is selected from hydrogen, or a methyl group, or a fluoromethyl group; comprising the steps:a. reacting an ester of formula 11 with substituted or unsubstituted ethylenediamine of formula 7 to give 3,4-dehydropiperazine-2-one and its derivatives of formula 12, wherein R, R1, R2 are as defined above and R6 is a C1 to C4 linear or branched alkyl group; andb. reacting the 3,4-dehydro-piperazine-2-one and its derivatives of formula 12 with a reducing agent to yield the piperazine and its derivatives of formula 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.