Triethylamine → Methanesulfonic Acid 2-[(2,3-dihydro-benzo[1,4]dioxin-5-yl)-(2-methanesulfonyloxy-ethyl)-amino]-ethyl ester

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Reaction Steps

To a solution of II (39.6 g, 0.165 mol) and triethyl amine (69 mL, 0.5 mol) in methylene chloride (250 mL), chilled to 5° C. in an ice-bath, is added a solution of mesyl chloride (38 mL, 0.5 mol) in methylene chloride (50 mL). The addition is carried out over 0.5 h at temperature not exceeding 18° C. The ice-bath is removed and resulting suspension is stirred at ambient temperature for 1 h. At that time, TLC and HPLC showed disappearance of starting material. The reaction mixture is washed with water (1×150 mL) and 5% aqueous NaHCO3 solution (1×150 mL), dried with MgSO4 and concentrated to afford III as red oil, crude yield 67.0 g (102%). 1H NMR (CDCl3) δ 6.85 (m, 1H), 6.63 (m, 2H), 4.28 (m, 8H), 3.55 (t, J=7.5 Hz, 4H), 2.97 (s, 6H).

Provenance & Evidence