摘要 |
<p>The invention relates to a method for the preparation of a cyclic compound according to formula III comprising reacting a compound according to Formula I and a compound according to formula II,
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wherein in Formula I, R<Sub>1</Sub>, R<Sub>2</Sub>, R<Sub>3</Sub> and R<Sub>4</Sub> may be hydrogen or substituent groups comprising one or more carbon atoms and/or hetero-atoms, wherein R<Sub>1</Sub>, R<Sub>2</Sub>, R<Sub>3</Sub> and R<Sub>4</Sub> can be combined in aromatic or aliphatic ring structures, - Y is a ring element comprising 1 - 3 substituted or unsubstituted carbon atoms and/or heteroatoms in the ring and - R<Sub>5</Sub> is hydrogen or a hydrocarbon substituent group comprising one or more carbon atoms and optionally one or more hetero atoms, and wherein in Formula II, Z<Sub>1</Sub> and Z<Sub>2</Sub> are, leaving groups, X is a reactive functional hydrocarbon group for subsequent ring closure, comprising one or more carbon atoms and a reactive functional group and having a chain of between 1 to 6 atoms between the carbon atom attached to the central carbon atom of formula II and the reactive functional group and R<Sub>8</Sub> is hydrogen or a hydrocarbon substituent different from X making the central carbon atom of formula II a chiral centre in Formula III and wherein reactive functional group X can be or can be extended to be compound of formula IV which can be ring closed to produce the polycyclic component of formula V. More in particular, the invention relates to the preparation of mirtazapine precursors and mirtazapine preferably having a substantial enantiomeric excess.</p> |