Purification of 5-pyrimidinecarboxamides
AssigneeUniroyal Chemical Ltd./Ltee
InventorArthur D. Brewer
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Abstract
A process is provided for the purification to highly purified states of 5-pyrimidinecarboxamides which are essentially insoluble in both organic and inorganic solvents. The 5-pyrimidinecarboxamide to be purified is contacted with an organic base having a pKa value in excess of 6.95 to form an adduct. The adduct is purified through recrystallization and the desired 5-pyrimidinecarboxamide is regenerated from the adduct in highly purified form with acid. Additionally, an adduct resulting from the combination of a 5-pyrimidinecarboxamide with such an organic base is provided, which adduct is capable of being purified using recrystallization techniques, where the 5-pyrimidinecarboxamide is not itself capable of being so purified due to its relative insolubility in organic and inorganic solvents.
Claims8
A process for purifying a 5-pyrimidine-carboxamide of the formula:
- ##STR2## wherein R is hydrogen, 2 or 3-halo, 2-methyl, 4-fluoro, 4-(C.sub.1 -C.sub.6 alkoxyl), 2 or 4-trifluoromethyl, or hydroxyl, and R.sub.1 is hydrogen;
- or
- R is 2-fluoro and R.sub.1 is 4-fluoro;
- or
- R is 2-methoxyl and R.sub.1 is 5-methyl;
- which consists essentially of
- (a) reacting the impure 5-pyrimidinecarboxamide with a pharmaceutically inert organic base having a pKa greater than 6.95 to form a crystalline adduct thereof;
- (b) dissolving the adduct in a solvent and cooling to recrystallize the adduct;
- and
- (c) treating the recrystallized adduct with acid to regenerate the 5-pyrimidinecarboxamide in substantially pure form.
Dependencies are inferred from the claim text.