2-Oxobutanoic Acid → HCID 12979375, compound
Reaction equation
[C:1]1([CH3:9])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH:7]N.O=[C:11]([CH2:15][CH3:16])[C:12]([OH:14])=[O:13].[CH2:17](O)[CH3:18]>>[CH3:16][C:15]1[C:3]2[C:2](=[C:1]([CH3:9])[CH:6]=[CH:5][CH:4]=2)[NH:7][C:11]=1[C:12]([O:14][CH2:17][CH3:18])=[O:13]Participants
4
Conditions
- Temperature
- 50 °C
Procedure
A suspension of 1-o-tolylhydrazine (3.8 g, 30.9 mmol) in ethanol was warmed to 50° C. A solution of α-ketobutyric acid (3.16 g, 30.9 mmol) in ethanol was added and the mixture stirred at rt overnight. Hydrogen chloride was bubbled through the solution for 30 min and the mixture heated at reflux for 2 h then evaporated in vacuo. The crude reaction was chromatographed over silica gel eluting with ethyl acetate/hexane (5%) to afford the title compound (1.84 g, 27%). 1H NMR (400 MHz, CDCl3) δ 8.55 (s, 1H), 7.50 (d, J=7.8 Hz, 1H), 7.09 (d, J=6.9 Hz, 1H), 7.03 (t, J=7.6 Hz, 1H), 4.41 (q, J=7.1 Hz, 2H), 2.59 (s, 3H), 2.48 (s, 3H), 1.44 (t, J=7.2 Hz, 3H).