反应详情

A solution of compound 4 (5.4 g 11 mmol) in methanol (300 mL) and 2.0 M NaOH (100 mL) was heated at 40° C. for 3 hrs. The solid was collected by filtration, and dried overnight under vacuum. The dry salt was dissolved in 40% acetonitrile/water, and was adjusted to pH 2 using concentrated HCl. The desired product compound 5 (3.8 g, 87%) was isolated as a white powder by filtration: 1H NMR (CDCl3) δ1.45 (s, 9H), 2.22 (dd, J=5.5 Hz, 6.1 Hz, 2H), 2.64 (dd, J=5.5 Hz, 6.1 Hz, 2H), 3.34 (dd, J=5.5 Hz, 6.1 Hz, 2H), 3.54 (dd, J=5.5 Hz, 6.1 Hz, 2H), 7.35 (d, J=6.7 Hz, 2H), 8.08 (d, J=6.7 Hz, 2H); 13 C NMR (CDCl3) δ28.3, 31.5, 34.2, 44.0, 115.3, 128.7, 129.4 130.3, 137.7, 145.2, 154.6, 170.3.

1. filtrationThe solid was collected by filtration
2. customdried overnight under vacuum
3. dissolutionThe dry salt was dissolved in 40% acetonitrile/water