反应详情

To a solution of the product (4.5 g, 2.48 mmol) from Step 2 in dioxane (2 mL) was added 4M HCl in dioxane (8 mL) at rt and the resulting mixture was stirred for 1 h at that temperature. The solvent was removed in vacuo to obtain a thick oil. The oil was triturated with ether to obtain a white solid (2.5 g). The solid was recrystallized with toluene (20 mL) to obtain the title product (1.8 g, 53%) as a crystalline solid: MS; m/z 268 (M+H): 1H NMR (400 MHz, DMSO-d6); δ 1.73 (m, 1H), 1.89 (m, 1H), 1.98 (m, 1H), 2.09 (m, 1H), 3.18 (m, 2H), 3.87 (m, 1H), 3.88 (s, 2H), 4.13 (dd, 1H, J1=7.2 Hz, J2=6.4 Hz), 4.19 (dd, 1H, J1=8.8, J2=3.2 Hz), 6.91 (d, 2H, J=6.8 Hz), 7.15-7.20 (m, 5H), 7.27 (m, 2H): HPLC (UV); 97.4%.

1. customThe solvent was removed in vacuo
2. customto obtain a thick oil
3. customThe oil was triturated with ether