Patent ID: 7307168

Claim:
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 and pharmaceutically acceptable acid addition salts thereof by subjecting the oxime of the Formula to ring-closure in the presence of an alkali hydroxide, alkali carbonate or alkali-C 1-4 -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 (wherein Hal is halogen) with piperidine oxime derivative of the Formula 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 C 1-4 -alkanol as inert solvent.