2,4-Dimethyl-6-oxo-1,6-dihydro-3-pyridinecarboxylic acid synthesis

Yield:24186-78-5 100%

Reaction Conditions:

with sulfuric acid;sodium nitrite in water at 0;

Steps:

13.1

EXAMPLE 13; [5-(-5-{3-[(3-Chloro-4-methyl-phenyl)-(4,4-difluoro-cyclohexanecarbonyl)-amino]-propyl}-hexahydro-pyrrolo[3,4-c]pyrrole-2-carbonyl)-4,6-dimethyl-2-oxo-2H-pyridin-1-yl]-acetic Acid Ethyl Ester (III-9) and [5-(5-{3-[(3-Chloro-4-methyl-phenyl)-(4,4-difluoro-cyclohexanecarbonyl)-amino]-propyl}-hexahydro-pyrrolo[3,4-c]pyrrole-2-carbonyl)-4,6-dimethyl-2-oxo-2H-pyridin-1-yl]-acetic Acid (III-10); step 1-; A solution of NaNO₂ (8.28 g, 0.12 mol) in H₂SO₄ (15% in water, 160 mL) was added dropwise at a rate of 1 drop per second to a solution of 2,4-dimethyl-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid amide (68a; 16.6 g, 0.1 mol) in H₂SO₄ (15% in water, 80 mL) cooled in a ice-water bath. The reaction was stirred overnight then poured into ice-cold water (1.5 L). The precipitate was filtered and washed with water (400 mL), Et₂O (350 mL) and dried to afford 16.7 g (100%) of 68b.

References:

US2007/191335,2007,A1 Location in patent:Page/Page column 34-35