反应详情

To a solution of 3.5 g (8.64 mmol) of the product of Step C in 30 mL of methanol was added 2.07 mL (10.37 mmol) of 5.0N aqueous sodium hydroxide solution. After stirring overnight, TLC analysis (80:15:1 chloroform/methanol/ammonium hydroxide) indicated that the saponification was complete. The reaction mixture was acidified to pH 3 with 6N aqueous HCl and concentrated in vacuo. With heating and sonnication, the residue was redissolved in ethyl acetate, washed with brine, dried over magnesium sulfate, filtered, and the filtrate evaporated in vacuo to afford 2.92 g (99%) of the title compound as an amorphous solid which was used without further purification in the next step.

1. concentrationconcentrated in vacuo
2. temperatureWith heating
3. dissolutionsonnication, the residue was redissolved in ethyl acetate
4. washwashed with brine
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. customthe filtrate evaporated in vacuo