Yield:98483-00-2 87%

Reaction Conditions:

in (2S)-N-methyl-1-phenylpropan-2-amine hydrate;sulfuric acid;

Steps:

96.2 2.

2. 3-Carboxy-6-isopropyl-2(1H)-pyridinone: 3-Cyano-6-isopropyl-2(1H)-pyridinone (2.92 g, 18.0 mmol), as prepared in the preceding step, was dissolved in hot 50% v/v sulfuric acid (45 mL) and refluxed for 3 hours. After cooling to ambient temperature, the reaction mixture was poured into 200 mL of ice water and the resulting precipitate collected by filtration, washed with water, then air and vacuum dried giving the title compound (2.83 g, 87%) as a white solid. ¹ H NMR (300 MHz, CDCl₃) δ 13.67 (s, 1H), 12.75 (br s, 1H), 8.56 (d, 1H, J=7.5 Hz), 6.56 (dd, 1H, J=7.6 Hz, 1.6 Hz), 3.02 (septet, 1H, J=6.9 Hz), 1.41 (s, 3H), 1.39 (s, 3H).

References:

US6037356,2000,A