反应详情

4-Carbmethoxybenzaldehyde (1ae, 0.62 g, 3.8 mmol) and acetone (19, 0.14 ml, 1.9 mmol) were combined in methanol (20 ml) and stirred under a nitrogen atmosphere for 15 min at room temperature. A solution of sodium hydroxide (0.15 g, 3.8 mmol) in water (5 ml) was added the mixture stirred for 18 hr at room temperature under a nitrogen atmosphere. The resulting precipitate was filtered and recrystallized from xylene to give 0.29 g (44%) of a yellow solid: mp 206-210° C. [expected mp 221-223° C.]; 1H NMR: δ 3.92 (s, 6H), 7.12 (d, 2H, J=16.1 Hz), 7.65 (d, 4H, J=8.1 Hz), 7.73 (d, 2H, J=15.9 Hz), 8.06 (d, 4H, J=8.0 Hz); 13C NMR: δ 52.3, 127.1, 128.1, 130.1, 131.6, 138.8, 142.1, 166.2, 188.0.

1. stirringstirred for 18 hr at room temperature under a nitrogen atmosphere
2. filtrationThe resulting precipitate was filtered
3. customrecrystallized from xylene