Triethylamine → Methanesulfonic acid 2-(1-benzyl-1H-indazol-6-yl)-2-methanesulfonyloxy-ethyl ester

Participants

Reaction Steps

A solution of 1-(1-Benzyl-1H-indazol-6-yl)-ethane-1,2-diol (0.27 g, 1.0 mmol) and Et3N (0.35 mL, 2.5 mmol) in dry CH2Cl2 (5 mL) was cooled in an ice bath before dropwise addition of MsCl (0.155 mL, 2.0 mmol) over 5 min. The resulting mixture was left to stir for 2 h, warming slowly to RT. After dilution with further CH2Cl2, the solution was washed quickly with 1.0 M aq. HCl (20 mL), sat. aq. NaHCO3 (40 mL) and brine (20 mL), dried over Na2SO4, filtered and concentrated at 25° C. to afford the crude product. The crude product was part-purified by rapid column chromatography on silica using 1:1 Et2O/CH2Cl2 as eluent, again concentrating at 25° C., giving the title compound (0.30 g, 71%) as an off-white, gummy foam. 1H NMR: (400 MHz, CDCl3) δ 8.08 (s, 1H), 7.81 (d, J=8.3 Hz, 1H), 7.42 (s, 1H), 7.34-7.23 (m, 3H), 7.17 (dd, J=18.1, 7.6 Hz, 3H), 5.89 (dd, J=8.5, 3.2 Hz, 1H), 5.66 (d, J=15.8 Hz, 1H), 5.60 (d, J=15.8 Hz, 1H), 4.52 (dd, J=11.8, 8.6 Hz, 1H), 4.40 (dd, J=11.8, 3.2 Hz, 1H), 3.04 (s, 3H), 2.75 (s, 3H). MS (ES+): 425 ([M+H]+), calcd for [C18H20N2O6S2+H]+ 425.1.

Provenance & Evidence