3-Pyridineacetic acid, 1,2-dihydro-4-methyl-2-oxo- synthesis

Yield:-

Reaction Conditions:

with water;hydrogen bromide at 20 - 100; for 29 h;

Steps:

1.e

(e) (4-Methyl-2-oxo-12-dil1ydropyridin-3-yl . acetic acid methyl ester; (2-Methoxy-4-methylpyridin-3-yl) acetonitrile (825 mg, 5.09 mmol ; see step (d) above) was dissolved in HBr (37%, 10 mL) and the solution was heated at 100°C for 5 hours and was further stirred at room temperature for 24 hours. The solvent was evaporated under reduced pressure and the resulting carboxylic acid was used directly in the next step. HCl (cone., 3 mL) was added to a solution of the crude acid (9.13 g, 50 mmol) in methanol (120 mL) and the reaction mixture was stirred for 10 hours at room temperature. The reaction mixture was then concentrated by evaporation under reduced pressure and the residue was dissolved in DCM and washed with NaHCO3. The organic layer was dried (Na2S04), filtered and the solvent was evaporated to give the sub-title compound (8.9 g, 97%). 1H NMR (400 MHz, CD30D) 6 2.12 (s, 3H), 3.56 (s, 2H), 3.60 (s, 3H), 6.07 (d, 1H), 7.15 (d, 1H)

References:

WO2005/75424,2005,A1 Location in patent:Page/Page column 99-100