反应详情

A mixture of Compound 1 (7.66 g, 50 mmole), which had been obtained in Preparation Example 1, and a 2 N aqueous solution of sodium hydroxide (37.5 ml, 75 mmole) was refluxed for 2 hours. The reaction mixture was cooled to 0° C., to which 6 N hydrochloric acid was added under stirring to acidify the same. Sodium chloride (15 g) was then added, followed by stirring for 1 hour over an ice-acetone bath. Precipitated crystals were collected. Those crystals were washed with chilled water and then dried under reduced pressure, whereby the title compound (5.77 g) was obtained (yield: 92.2%).

1. customhad been obtained in Preparation Example 1
2. additionwas added
3. stirringby stirring for 1 hour over an ice-acetone bath
4. customPrecipitated crystals
5. customwere collected
6. washThose crystals were washed with chilled water
7. dry with materialdried under reduced pressure, whereby the title compound (5.77 g)
8. customwas obtained (yield: 92.2%)