6-Nitro-4-(2-(pyrrolidin-1-yl)ethyl)-3,4-dihydro-2H-benzo[b][1,4]thiazine → HCID 178511893, compound

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Reaction Steps

To a stirred solution of 6-nitro-4-(2-(pyrrolidin-1-yl)ethyl)-3,4-dihydro-2H-benzo[b][1,4]thiazine (649 mg, 2.212 mmol) in ethanol (5 mL) was added palladium, 10 wt. % on activated carbon (235 mg, 0.221 mmol) as a suspension in ethanol (5 mL). The resulting suspension was stirred under an atmosphere of hydrogen (balloon pressure) for 3 hours (yellow color disappears). The balloon was removed, and methyl thiophene-2-carbimidothioate hydroiodide (1.262 g, 4.42 mmol) was added to the mixture. The resulting mixture was stirred under argon overnight at room temperature. The mixture was then diluted with dichloromethane and filtered through Celite. The filtrate was then diluted with saturated sodium carbonate and extracted with dichloromethane (2×). The combined organics were dried, filtered, concentrated, and then chromatographed in 1:19 (2M NH3 in methanol):ethyl acetate, giving the desired product 25 (438 mg, 53.1%). 1H NMR (DMSO-d6) δ 7.71 (d, J=3.3 Hz, 1H), 7.58 (d, J=5.1 Hz, 1H), 7.10-7.06 (m, 1H), 6.83 (d, J=8.1 Hz, 1H), 6.38 (brs, 2H), 6.19 (s, 1H), 6.08 (d, J=1H), 3.63-3.58 (m, 2H), 3.40-3.33 (m, 2H), 3.01-2.97 (m, 2H), 2.61 (t, J=6.8 Hz, 2H), 2.49-2.42 (m, 4H), 1.70-1.61 (m, 4H); ESI-MS (m/z, %): 373 (MH+, 62), 276 (100); HRMS calculated for C19H25N4S2 (MH+), calculated: 373.1515, observed: 373.1512; HPLC purity: 97% by area.

Provenance & Evidence