Process for the preparation of high purity O-substituted hydroxylamine derivatives
US5777164A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1997 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Apr 14, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C239/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The present invention discloses a method comprising the steps of; a) forming in an aqueous solution a hydroxamic acid from a hydroxylamine free base and anhydride having the formula (RCO).sub.2 O wherein R is H or a substituted or unsubstituted C.sub.2-6 alkyl, C.sub.2-6 alkenyl, C.sub.6-10 aryl, or C.sub.4-10 heteroaryl; and b) treating said hydroxamic acid with an alkylating agent in the presence of at least one proton scavenger under conditions sufficient to consume substantially all of said alkylating agent to form an O-substituted hydroxamate. The protection and alkylation are readily effected in water (with no alcohol co-solvent) without the need for phase-transfer catalysis and with little hydrolysis of the alkylating agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.