反应详情

To a stirred solution of the product of step 1 (10.0 g, 2.50 mmol), in 1:1 ethanol/tetrahydrofuran (110 mL) was added 1.0 N aqueous sodium hydroxide solution (55 (mL). The mixture was stirred for 1 hour, concentrated and redissolved in water (150 (mL). While stirring, the solution was acidified with the addition of 1.0 N aqueous hydrochloric acid (55 mL). The resulting white precipitate was collected by filtration, rinsed with water and vacuum oven dried to afford 8.55 g (89%) of product as a white solid. In chloroform-d solvent, the proton NMR spectra of this compound appears as a 6:4 mixture of rotamers: 1H NMR (CDCl3) δ 7.44-6.78 (m, 13H), 5.29 (t, J=5.7 Hz, 0.6H), 5.18 (d, J=17.9 Hz, 0.4H), 4.81-4.73 (m, 0.4H), 4.62-4.47 (m, 1.6H), 3.30-3.15 (m, 1.6H), 3.13-3.01 (m, 0.4H) ppm.

1. concentrationconcentrated
2. dissolutionredissolved in water (150 (mL)
3. stirringWhile stirring
4. additionthe solution was acidified with the addition of 1.0 N aqueous hydrochloric acid (55 mL)
5. filtrationThe resulting white precipitate was collected by filtration
6. washrinsed with water and vacuum oven
7. customdried