Ammonia → 2-(2-Hydroxyethylamino)-1-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanone

Participants

Reaction Steps

A solution of 2-chloro-1-(7-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanone (1.0 g, 3.67 mmol) in THF (20 mL) was treated with 4M HCl in 1,4-dioxane (4.58 mL, 18.33 mmol), followed by the slow addition of a solution of 2-aminoethanol (2.207 mL, 36.7 mmol) in water (4 mL). The dark solution was stirred at room temperature for 24 hours. The mixture was diluted with EtOAc (50 mL) and saturated sodium bicarbonate (100 mL), then stirred for 20 minutes. The contents were poured into a separatory funnel, and the organic layer was separated, dried (Na2SO4), filtered, and concentrated to give a dark yellow residue. This residue was subjected to flash chromatography on silica gel using 5:95 MeOH:CH2Cl2 followed by 5:95 (2M NH3 in MeOH):CH2Cl2 to give a yellow residue (320 mg, 29.4%). 1H-NMR (CDCl3) δ 8.14 (d, J=2.7 Hz, 1H), 7.95 (dd, J=2.7, 9.0 Hz, 1H), 7.37 (d, J=9.0 Hz, 1H), 4.02 (t, J=5.1 Hz, 2H), 3.61 (t, J=5.1 Hz, 2H), 3.57 (s, 2H), 3.28 (t, J=5.4 Hz, 2H), 2.77 (t, J=4.8 Hz, 2H); ESI-MS (m/z, %): 298 (MH+, 100%).

Provenance & Evidence