PROCESS FOR THE PREPARATION OF 3-{2-[4-(6-FLUORO-1,2-BENZIZOXAZOL-3-YL)-1-PIPERIDINYL]-ETHYL}-6,7,8,9-TETRAHYDRO-2-METHYL-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE

• Main Authors: CLEMENTIS GYOERGY DR, PONGO LASZLO DR, NAGY KALMAN DR, SLEGEL PETER DR, VERECZKEYNE DONATH GYOERGYI DR, KOERTVELYESSY GYULANE DR, BERECZ GABOR DR, REITER JOZSEF DR, SZULAGYI JANOS, KONCZ LASZLO, SIMIG GYULA DR
• Format: Patent
• Language: English
• Published: 28.07.2010
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

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.