反应详情

To a stirred solution of ix (76 g, 0.187 mol) in DCM (1.7 L) was added methane sulfonic acid (270 mL, 4.17 mol) dropwise over 30 min. The mixture was stirred at RT for 3 h. The reaction was concentrated in vacuo. EtOAc (1 L) was added to the residue and this solution was poured carefully onto the crushed ice. The pH of the solution was modified to 8-9 by addition of saturated NaHCO3 solution followed by extraction with EtOAc (3×5 L). The combined organics were washed with H2O, brine, dried (Na2SO4), filtered and concentrated in vacuo. The residue was stirred in Et2O (1.0 L) for 1 h at RT and then filtered to obtain x (57.0 g, 97%). 1H-NMR (DMSO-d6, 400 MHz): δ 1.08 (t, J=7.20 Hz, 3H), 3.20 (m, 2H), 6.86 (br s, 1H), 7.0 (s, 1H), 7.46 (s, 2H), 7.96 (m, 1H), 8.10 (m, 1H), 8.76 (m, 1H), 9.59 (br s, 1H) and 10.41 (br s, 1H). MS: 315.06 [M+H]+.

1. concentrationThe reaction was concentrated in vacuo
2. additionEtOAc (1 L) was added to the residue
3. additionthis solution was poured carefully onto the crushed ice
4. additionThe pH of the solution was modified to 8-9 by addition of saturated NaHCO3 solution
5. extractionfollowed by extraction with EtOAc (3×5 L)
6. washThe combined organics were washed with H2O, brine
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. stirringThe residue was stirred in Et2O (1.0 L) for 1 h at RT
11. filtrationfiltered
12. customto obtain x (57.0 g, 97%)