反应详情

400 mg of the compound obtained in Example 22 was dissolved in a mixture consisting of 5 ml of ethanol and 2.9 ml of a 1N aqueous solution of sodium hydroxide, and the resulting solution was stirred for 4 hours. After the reaction mixture was concentrated under reduced pressure, it was dissolved in 40 ml of water and a small amount of insoluble matter was removed. Then, the aqueous solution was adjusted to pH 2 with concentrated hydrochloric acid. The precipitated crystals were separated by filtration and washed with water to obtain 280 mg of the desired compound.

1. concentrationAfter the reaction mixture was concentrated under reduced pressure, it
2. dissolutionwas dissolved in 40 ml of water
3. customa small amount of insoluble matter was removed
4. customThe precipitated crystals were separated by filtration
5. washwashed with water