反应详情

To a stirred mixture of 4-formylbenzoic acid (1.5 g, 10 mmol) in anhydrous dichloromethane (30 mL) was added triethylamine (2.52 g, 25 mmol), 1-hydroxybenzotriazole (1.5 g, 11 mmol), followed by 1-ethyl-3-(3-dimethylamino propyl)carbodiimide hydrochloride (2.1 g, 11 mmol). After the addition, the mixture was stirred at room temperature for 40 mins. Then the mixture was cooled to 0° C. and 2-methyl-1-(piperazin-1-yl)propan-1-one (2.12 g, 11 mmol) was added in portion-wise. After the addition, the mixture was allowed to stir at room temperature overnight. The mixture was diluted with dichloromethane (50 mL), washed with saturated citric acid (100 mL×2), followed by saturated sodium bicarbonate (100 mL×2), brine (50 mL), dried over anhydrous sodium sulfate, and concentrated to give 4-(4-isobutyrylpiperazine-1-carbonyl)benzaldehyde (2 g, yield 70%) as a light yellow oil. 1H-NMR (400 MHz, CDCl3) δ (ppm): 1.15 (d, 6H), 2.80 (brs, 1H), 3.39-3.80 (m, 8H), 7.58 (d, J=8.0 Hz, 1H), 7.95 (d, J=8.0 Hz, 1H), 10.07 (s, 1H); LC-MS (ESI) m/z: 289 (M+1)+.

1. additionAfter the addition
2. temperatureThen the mixture was cooled to 0° C.
3. additionAfter the addition
4. stirringto stir at room temperature overnight
5. washwashed with saturated citric acid (100 mL×2)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated