4H-​Pyrido[1,​2-​a]​pyrimidin-​4-​one, 3-​[2-​[4-​[4-​fluoro-​2-​[4-​(6-​fluoro-​1,​2-​benzisoxazol-​3-​yl)​-​1-​piperidinyl]​benzoyl]​-​1-​piperidinyl]​ethyl]​-​6,​7,​8,​9-​tetrahydro-​2-​methyl-