Synthesis of antidiabetic rosigltazone derivatives
AssigneeCipla Limited
InventorsDharmaraj Rao, Rajendra Kankan
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Abstract
A process of preparing rosiglitazone, or a pharmaceutically acceptable salt thereof, which process employs an intermediate metabisulphite complex of 4-[2-(N-methyl-N-(2-pyridyl)amino) ethoxy] benzaldehyde, which metabisulphite complex is represented by following formula (III); where X represents an alkali metal. The present invention further provides rosiglitazone, or a pharmaceutically acceptable salt thereof, prepared by the above process.
Claims46
A process of preparing rosiglitazone of formula (I), or a pharmaceutically acceptable salt thereof,
- which process employs an intermediate metabisulphite complex of 4-[2-(N-methyl-N-(2-pyridyl)amino) ethoxy] benzaldehyde, which metabisulphite complex is represented by following formula (III):
- where X represents an alkali metal.
19-21. (canceled)
28-32. (canceled)
A process of preparing rosiglitazone of formula (I), or a pharmaceutically acceptable salt thereof,
- which process includes an intermediate process step wherein an intermediate benzaldehyde compound of formula (IV):
- is prepared from an intermediate compound of formula (V):
- wherein intermediate compound of formula (V) and a 4-Hal benzaldehyde, where Hal represents bromo, chloro, fluoro or iodo, are dissolved in a polar aprotic solvent followed by sequential additions of sodium hydride in increasing molar quantities.
A metabisulphite complex of formula (III):
- where X represents an alkali metal.
52-64. (canceled)
Dependencies are inferred from the claim text.