HCID 178483720, compound → HCID 178483718, compound

Participants

Reaction Steps

A suspension of tert-butyl methyl(3-(7-(thiophene-2-carboximidamido)-2H-benzo[b][1,4]thiazin-4(3H)-yl)propyl)carbamate (0.55 g, 1.231 mmol) in 3M hydrochloric acid (25 mL) was refluxed for 1 hour. The reaction was brought to room temperature, filtered, and washed with water (2×10 mL). The combined aqueous layers were evaporated. The crude material was basified with 3 M NaOH solution (50 mL), and the product was extracted into CH2Cl2 (3×20 mL). The combined CH2Cl2 layers were washed with brine (15 mL) and dried (Na2SO4). The organic solvent was evaporated, and the crude material was purified by column chromatography (5:95 to 1:9 (2M NH3 in MeOH):CH2Cl2) on silica gel to obtain compound 23 (0.4 g, 94%) as a solid. 1H NMR (DMSO-d6) δ 7.68 (dd, 1H, J=1.2, 3.7 Hz), 7.56 (dd, 1H, J=0.9, 5.1 Hz), 7.06 (dd, 1H, J=3.6, 4.9 Hz), 6.70 (d, 1H, J=8.7 Hz), 6.51-6.44 (m, 2H), 6.31 (s, 2H), 3.50-3.47 (m, 2H), 3.32-3.25 (m, 4H), 3.04-3.01 (m, 2H), 2.27 (s, 3H), 1.70-1.61 (m, 2H); ESI-MS (m/z, %): 347 (MH+, 80), 276 (100); HPLC purity: 96.05% by area.

Provenance & Evidence