反应详情

温度

115 °C

Compound 52A (268 mg, 1.44 mmol), triethyl orthoformate (2.4 ml, 14.36 mmol) and para-toluenesulfonic acid (27.3 mg, 0.144 mmol) were combined and heated at 115° C. overnight. Precipitation occurred upon cooling to room temperature. The precipitate was collected via filtration, rinsed with diethyl ether and dried under reduced pressure to yield the title compound 52B: 1H NMR (300 MHz, DMSO-d6) δ ppm 8.81 (1H, s), 8.78 (1H, s), 4.89 (1H, m), 1.58 (6H, d).

1. customPrecipitation
2. temperatureupon cooling to room temperature
3. filtrationThe precipitate was collected via filtration
4. washrinsed with diethyl ether
5. customdried under reduced pressure