Process for the preparation of 3-{2-′4- (6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyllethyl}-6,7,8,9-tetrahydro-2-methyl-4h-pyrido′1,2-methyl-4h-pyrido′,2-a!pyrimidin-4-one
US7307168B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 2002 |
| Grant date | Dec 11, 2007 |
| Priority date | — |
| Expiry date | Apr 5, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D471/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of 3-{2-[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]ethyl}-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one of the Formula (I), and pharmaceutically acceptable acid addition salts thereof by subjecting the oxime of the Formula (II), to ring-closure in the presence of an alkali hydroxide, alkali carbonate or alkali-C1-4 alkoxide in an inert organic solvent, converting the base of the Formula I thus obtained into an acid addition salt or setting free the base of the Formula I from an acid addition salt thereof which comprises reacting a halogen derivative of the general Formula (XIV), (wherein Hal is halogen) with piperidine oxime derivative of the Formula (V), or an acid addition salt thereof in the presence of a base, and using by the ring-closure of the oxime of the Formula II formed a C1-4-alkanol as inert solvent. The process of the present invention enables the economical preparation of a product having a purity suitable for pharmaceutical purposes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.