Process for preparing pyridine 2-carboxamides
AssigneeHoffmann-La Roche Inc.
InventorsMichelangelo Scalone, Peter Vogt
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AssigneeHoffmann-La Roche Inc.
InventorsMichelangelo Scalone, Peter Vogt
Estimating the term…
It has been found that pyridine-2-carboxamides of the formula ##STR1## wherein R is amino or a residue convertible into amino, and pharmaceutically usable acid addition salts of that carboxamide in which R is amino can be prepared in a simple manner and in good yield by reacting 2,5-dichloropyridine in the presence of a palladium-phosphine catalyst with an alkyne of the formula R.sup.1 -C.tbd.CH III wherein R.sup.1 is hydrogen, lower-alkyl, trimethylsilyl or the group --(R.sup.2)(R.sup.3)--COH and R.sup.2 and R.sup.3 each independently are hydrogen or lower-alkyl or together are cyclopentyl or cyclohexyl, oxidizing the resulting alkyne to give 5-chloropyridine-2-carboxylic acid and reacting this acid or a reactive functional derivative thereof with an amino compound of the formula VI. The compound of formula I in which R is amino is a known compound which is a reversible and highly active MAO-B inhibitor.
A process for the preparation of pyridine-2-carboxamides of the formula ##STR13## wherein R is amino or a residue convertible into amino, which comprises reacting 2,5-dichloropyridine of the formula ##STR14## in the presence of a palladium-phosphine catalyst with an alkyne of the formula
Dependencies are inferred from the claim text.