Hydrochloric Acid → 1-(6-Nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)-2-(pyrrolidin-1-yl)ethanone

HRID 424561Notes

Reaction equation

Cl[CH2:2][C:3]([N:5]1[CH2:10][CH2:9][S:8][C:7]2[CH:11]=[CH:12][C:13]([N+:15]([O-:17])=[O:16])=[CH:14][C:6]1=2)=[O:4].Cl.C(OCC)C.[NH:24]1[CH2:28][CH2:27][CH2:26][CH2:25]1>O1CCOCC1.C(OCC)(=O)C.O>[N+:15]([C:13]1[CH:12]=[CH:11][C:7]2[S:8][CH2:9][CH2:10][N:5]([C:3](=[O:4])[CH2:2][N:24]3[CH2:28][CH2:27][CH2:26][CH2:25]3)[C:6]=2[CH:14]=1)([O-:17])=[O:16]

Participants

Conditions

Temperature: 0 °C

Procedure

To a stirred solution of 2-chloro-1-(6-nitro-2H-benzo[b][1,4]thiazin-4(3H)-yl)ethanone (685 mg, 2.51 mmol) in dioxane (10 mL), cooled to 0° C. was added HCl, 1 M in diethyl ether (2.51 mL, 2.51 mmol) followed by pyrrolidine (0.21 mL, 2.51 mmol) dropwise. The resulting mixture was stirred at 0° C. for 5 minutes and then warmed to room temperature, stirring overnight. At this time, additional pyrrolidine (0.21 mL, 2.51 mmol) was added, followed by water (1 mL) to aid dissolution. After 1 hour of stirring at room temperature, the mixture was then diluted with ethyl acetate and washed with saturated sodium carbonate, water (3×), and brine. The organic phase was dried, filtered, and concentrated, giving a yellow/orange oil (756 mg, 98%). 1H NMR (DMSO-d6) δ 8.52 (brs, 1H), 7.93 (dd, J=9.0, 1.6 Hz, 1H), 7.49 (d, J=9.0 Hz, 1H), 4.01-3.91 (m, 4H), 3.56 (s, 2H), 3.45-3.35 (m, 2H), 2.55-2.50 (m, 2H), 2.22-2.14 (m, 4H); ESI-MS (m/z, %): 308 (MH+, 100).

Workup

temperaturewarmed to room temperature
stirringstirring overnight
dissolutiondissolution
stirringAfter 1 hour of stirring at room temperature
washwashed with saturated sodium carbonate, water (3×), and brine
customThe organic phase was dried
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-be419f82cab7419794ecacb7a979e55d
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08106043B2

Reaction notes

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