反应详情

温度

60 °C

To a solution of 3-cyclopentyl-3-oxo-propionic acid ethyl ester (5.0 g, 27.4 mmol) and guanidine hydrochloride (3.1 g, 33.0 mmol) in MeOH (50 mL) at 23° C. was added potassium tert-butoxide, portionwise (16.7 g. 149 mmol) over 15 min with vigorous stirring and the reaction warmed to 60° C. The reaction was cooled to room temperature (rt) and stirred overnight and the precipitated salt was removed by filtration. The solution was concentrated to approximately 10 mL then diluted with 10 mL of water and adjusted to pH=5 by the addition of 6.0 N HCl (6.1 mL). The resulting precipitate was filtered and dried via suction then vacuum to yield a white solid (4.3 g, 87%) that was used without further purification. 1H NMR (MeOD): 10.71-10.54 (m, 1H), 6.58-6.32 (m, 2H), 5.44-5.37 (m, 1H), 2.66 (p, J=8.1, 1H), 1.91-1.73 (m, 2H), 1.72-1.48 (m, 6H).

1. temperatureThe reaction was cooled to room temperature (rt)
2. stirringstirred overnight
3. customthe precipitated salt was removed by filtration
4. concentrationThe solution was concentrated to approximately 10 mL
5. additionthen diluted with 10 mL of water
6. additionadjusted to pH=5 by the addition of 6.0 N HCl (6.1 mL)
7. filtrationThe resulting precipitate was filtered
8. customdried via suction