Hydrochloric Acid → HCID 178511892, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of tert-butyl 4-(6-(thiophene-2-carboximidamido)-2H-benzo[b][1,4]thiazin-4(3H)-yl)piperidine-1-carboxylate (398 mg, 0.868 mmol) in MeOH (6 mL) was added aqueous hydrogen chloride, 3M (2.893 mL, 8.68 mmol). The resulting solution was stirred at 90° C. for 45 minutes The mixture was then cooled to room temperature, basified (pH 12) with saturated sodium carbonate, and then extracted with dichloromethane (3×). The combined organics were dried, filtered, concentrated, and then chromatographed in 1:6 (2M NH3 in MeOH):ethyl acetate to give the desired product 29 (216 mg, 69.4%) as a pale yellow foam. 1H NMR (DMSO-d6) δ 7.71 (d, J=2.7 Hz, 1H), 7.59 (d, J=4.8 Hz, 1H), 7.08 (dd, J=5.1, 3.6 Hz, 1H), 6.86 (d, J=8.1 Hz, 1H), 6.37 (brs, 2H), 6.26 (s, 1H), 6.13-6.08 (m, 1H), 3.68-3.52 (m, 1H), 3.43-3.38 (m, 2H), 3.01-2.93 (m, 4H), 2.61-2.51 (m, 2H), 1.64-1.52 (m, 4H); ESI-MS (m/z, %): 359 (MH+, 100); ESI-HRMS calculated for C18H23N4S2 (MH+), calculated: 359.1358, observed: 359.1351; HPLC purity: 97% by area.

Provenance & Evidence