反应详情

4.1 g of the compound obtained in Example 1 was suspended in 50 mL of 15% aqueous ethanol at 60° C. The compound was dissolved by the addition of 7.42 mL of a 1 mol/L solution of p-toluenesulfonic acid in ethanol and then an additional 40 mL of 15% aqueous ethanol. Then, the solution was cooled to room temperature and stirred for 1 day. Deposited crystals were collected by filtration, washed with ethanol, and then dried under reduced pressure at room temperature for 2 hours to obtain 4.7 g of the title crystals (86%). Melting point (decomp.): 246 to 250° C.

1. filtrationDeposited crystals were collected by filtration
2. washwashed with ethanol
3. customdried under reduced pressure at room temperature for 2 hours