Process for the manufacture of cyclopropylamine
US4590292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1985 |
| Grant date | May 20, 1986 |
| Priority date | — |
| Expiry date | Jun 10, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A modified novel process for preparing cyclopropylamine from .gamma.-butyrolactone is described. The .gamma.-butyrolactone ring is cleaved with a hydrohalide in the presence of a novel catalyst comprising an aqueous sulfuric acid solution. The 4-chlorobutyric acid, thus formed is converted into a hindered chlorobutyrate ester. The hindered ester based on secondary and tertiary alkanols of eight or less carbon atoms, is cyclized to form the hindered cyclopropanecarboxylate ester by a novel reaction medium consisting of solid caustic in a water-immiscible solvent and a phase transfer catalyst. The hindered cyclopropanecarboxylate ester is ammoniated to form cyclopropanecarboxamide by a novel catalyst comprising an alkali metal salt of a polyol having hydroxy groups on adjacent carbons. The carboxamide formed in substantially quantitative yields is converted to cyclopropylamine by a modified Hofmann reaction utilizing continuous degradation of the intermediate with simultaneous distillation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.