Abstract |
L-869298 is a potent and selective phosphodiesterase-4 ( PDE4) inhibitor, which is potentially useful in the treatment of asthma and chronic obstructive pulmonary disorder. A catalytic asymmetric synthesis that is suitable for the preparation of kilogram quantities of L-869298, and which does not require the use of chromatography, has been developed to support the on-going drug development program of L-869298 at Merck Research Laboratories. The catalytic asymmetric hydrogenation of an aromatic heteroaromatic ketone afforded the corresponding alcohol in almost perfect enantioselectivity. Activation of the alcohol via formation of the 4-toluenesulfonate, followed by an unprecedented displacement of the tosylate via the lithium enolate of ethyl-3-pyridyl acetate N- oxide, generated the chiral tetra-substituted ethane. The displacement reaction proceeded with inversion of configuration and without loss of optical purity. Deprotection of the displacement adduct followed by decarboxylation, afforded L-869298 in excellent overall yield. The methodology developed could be readily extended to the synthesis of several other chiral PDE4 inhibitors.
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Authors | Cheng-Yi Chen |
Journal | Current opinion in drug discovery & development
(Curr Opin Drug Discov Devel)
Vol. 8
Issue 6
Pg. 709-22
(Nov 2005)
ISSN: 1367-6733 [Print] England |
PMID | 16312147
(Publication Type: Journal Article)
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Chemical References |
- Cyclic N-Oxides
- Enzyme Inhibitors
- L 869298
- Pyridines
- Thiazoles
- 3',5'-Cyclic-AMP Phosphodiesterases
- Cyclic Nucleotide Phosphodiesterases, Type 4
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Topics |
- 3',5'-Cyclic-AMP Phosphodiesterases
(antagonists & inhibitors)
- Catalysis
- Cyclic N-Oxides
(chemical synthesis)
- Cyclic Nucleotide Phosphodiesterases, Type 4
- Enzyme Inhibitors
(chemical synthesis, pharmacology)
- Molecular Structure
- Pyridines
(chemical synthesis)
- Stereoisomerism
- Thiazoles
(chemical synthesis)
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