Processes for the manufacturing of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide
AssigneeApotex Inc.
InventorsTim F. Tam, Wanren Li
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Abstract
The present invention relates to a novel process for the preparation of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I: The method comprises of the TEMPO oxidation of a primary alcohol of 3-O-protected-2-hydroxymethyl-6-alkyl-4H-pyran-4-one of formula III to 3-O-protected-6-alkyl-4-oxo-4H-pyran-2-carboxylic acid of formula II. Reaction of compound of formula II with methylamine and 1,1-carbonyldiimidazole in an inert solvent affords 3-O-protected-N, 1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide, which is deprotected to give of 3-hydroxy-N,1,6-trialkyl-4-oxo-1,4-dihydropyridine-2-carboxamide of formula I.
Claims3
A process for the preparation of a compound of formula I:
- wherein:
- R1 is hydrogen or a lower alkyl,
- R2 is hydrogen or a lower alkyl,
- R4 is a lower alkyl, hydrogen, or a lower alkoxy,
- R5 is hydrogen or an alcohol protective group;
- comprising:
- (i) reacting a compound of formula II:
- wherein:
- R1, R4 and R5 are as defined above, with 1,1′-carbonyldiimidazole;
- and
- (ii) reacting the mixture resulting from step (i) with a compound of formula R2NH2,
- wherein R2 is as defined above, so that the compound of formula I is produced.
Dependencies are inferred from the claim text.