Potassium Carbonate → 4-(2-(Dimethylamino)ethyl)-7-nitro-2H-benzo[b][1,4]thiazin-3(4H)-one

HRID 424485Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[NH:12][C:11](=[O:13])[CH2:10][S:9][C:8]=2[CH:14]=1)([O-:3])=[O:2].C(=O)([O-])[O-].[K+].[K+].Cl.Cl[CH2:23][CH2:24][N:25]([CH3:27])[CH3:26]>CN(C=O)C.O>[CH3:26][N:25]([CH3:27])[CH2:24][CH2:23][N:12]1[C:11](=[O:13])[CH2:10][S:9][C:8]2[CH:14]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=[CH:6][C:7]1=2

Participants

Conditions

Temperature: 90 °C

Procedure

To a stirred suspension of 7-nitro-2H-benzo[b][1,4]thiazin-3(4H)-one (1.02 g, 4.85 mmol) and potassium carbonate (4.69 g, 34.0 mmol) in a pressure flask in DMF (30 mL) under argon was added 2-chloro-N,N-dimethylethanamine hydrochloride (3.49 g, 24.26 mmol). The flask was immediately sealed and heated with stirring to 90° C. overnight. The mixture was then cooled to room temperature, diluted with water and extracted (2× ethyl acetate). The combined organics were then washed with a 1:1 mixture of brine and water (3×) then brine (1×). The organic phase was dried, filtered, concentrated, and then chromatographed in 5% (2M NH3 in MeOH) in dichloromethane, giving the desired product (755 mg, 55.3%). 1H NMR (DMSO-d6) δ 8.30 (d, J=2.7 Hz, 1H), 8.13 (dd, J=9.3, 2.7 Hz, 1H), 7.59 (d, J=9.3 Hz, 1H), 4.11 (t, J=6.9 Hz, 2H), 3.62 (s, 2H), 2.41 (t, J=6.9 Hz, 2H), 2.17 (s, 6H); MS-EI: (m/z, %) 281 (M+, 55), 251 (65), 58 (100).

Workup

customThe flask was immediately sealed
temperatureheated
temperatureThe mixture was then cooled to room temperature
extractionextracted (2× ethyl acetate)
washThe combined organics were then washed with a 1:1 mixture of brine and water (3×)
customThe organic phase was dried
filtrationfiltered
concentrationconcentrated
customchromatographed in 5% (2M NH3 in MeOH) in dichloromethane

Sources & evidence

ORD record: ord-2c422631fb954ade99460216637e58b6
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08106043B2

Reaction notes

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