Triethylamine → 3-(4-Isobutyrylpiperazine-1-carbonyl)benzaldehyde

To a solution of 3-formylbenzoic acid (750 mg, 5 mmol) in anhydrous dichloromethane (15 mL) was added triethylamine (1.263 g, 12.5 mmol), 1-hydroxybenzotriazole (0.743 g, 5.5 mmol), followed by 1-ethyl-3-(3-dimethylamino propyl)carbodiimide hydrochloride (1.05 g, 5.5 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 hydrochloride (1.06 g, 5.5 mmol) was added portionwise. After the addition, the mixture was stirred at room temperature overnight. The mixture was diluted with dichloromethane (50 mL), washed with saturated sodium bicarbonate (50 mL×2), 10% citric acid (50 mL), brine (30 mL), dried over anhydrous sodium sulfate, and concentrated to give 3-(4-isobutyrylpiperazine-1-carbonyl)benzaldehyde (1.44 g, yield 95%) as a gum. 1H-NMR (400 MHz, CDCl3) δ (ppm): 1.13-1.14 (d, J=6.8 Hz, 6H), 2.80 (s, 1H), 3.46-3.80 (m, 8H), 7.62-7.66 (t, J=7.6 Hz, 1H), 7.69-7.71 (d, J=7.6 Hz, 1H), 7.94 (s, 1H), 7.96-7.99 (dd, J1=7.6 Hz, J2=1.2 Hz, 1H), 10.06 (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. stirringthe mixture was stirred at room temperature overnight
5. washwashed with saturated sodium bicarbonate (50 mL×2), 10% citric acid (50 mL), brine (30 mL)
6. dry with materialdried over anhydrous sodium sulfate
7. concentrationconcentrated

ORD record

ord-21241ccf6d3c402594e6af3347c88f01

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08012976B2