Benzo(d)thiazol-2-amine → (2E)-N-(1,3-benzothiazol-2-yl)-2-(3-chloro-4-methylsulfonylphenyl)-2-cyclopentyloxyiminoacetamide
Reaction equation
[Cl:1][C:2]1[CH:3]=[C:4](/[C:12](=[N:16]\[O:17][CH:18]2[CH2:22][CH2:21][CH2:20][CH2:19]2)/[C:13]([OH:15])=O)[CH:5]=[CH:6][C:7]=1[S:8]([CH3:11])(=[O:10])=[O:9].[NH2:23][C:24]1[S:25][C:26]2[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=2[N:28]=1.C(N(CC)C(C)C)(C)C>C(#N)C>[S:25]1[C:26]2[CH:32]=[CH:31][CH:30]=[CH:29][C:27]=2[N:28]=[C:24]1[NH:23][C:13](=[O:15])/[C:12](/[C:4]1[CH:5]=[CH:6][C:7]([S:8]([CH3:11])(=[O:9])=[O:10])=[C:2]([Cl:1])[CH:3]=1)=[N:16]/[O:17][CH:18]1[CH2:22][CH2:21][CH2:20][CH2:19]1Participants
Procedure
(E)-(3-Chloro-4-methanesulfonyl-phenyl)-cyclopentyloxyimino-acetic acid (prepared as in Example 1, 96 mg, 0.28 mmol), 2-aminobenzothiazole (42 mg, 0.28 mmol) and N,N-diisopropylethylamine (145 μL, 0.83 mmol) were combined in acetonitrile (1.25 mL) and cooled in an ice bath. O-(7-Azabenzotriazole-1-yl)-N,N,N′N′-tetramethyluronium hexafluorophosphate (106 mg, 0.28 mmol) was added and the ice bath was removed. After stirring 2 h, the reaction mixture was evaporated in vacuo. The residue was treated with saturated aqueous sodium bicarbonate solution (1 mL) and extracted with chloroform (2×3 mL). The combined organic phases were dried over sodium sulfate and evaporated in vacuo. The residue was purified by flash column chromatography (Merck silica gel 60, 40-63 μm; 40% ethyl acetate/hexanes) to afford (E)-N-benzothiazol-2-yl-2-(3-chloro-4-methanesulfonyl-phenyl)-2-cyclopentyloxyimino-acetamide (93 mg, 70%) as a white solid after lyophilization from aqueous acetonitrile: LC-MS (ESI) m/e calcd for C21H20ClN3O4S2 [M+] 477.06, found 478 [M+H+]; H1-NMR (400 MHz, CDCl3) δ ppm 1.68 (m, 4 H, 2×CH2), 1.90 (m, 4 H, 2×CH2), 3.32 (s, 3 H, SO2CH3), 4.96 (m, 1 H, OCH), 7.35 (ddd, Jo=7.9, Jo=7.3, Jm=1.2 Hz, 1 H, Ar), 7.48 (ddd, Jo=8.2, Jo=7.3, Jm=1.2 Hz, 1 H, Ar), 7.61 (dd, Jo=8.2, Jm=1.6 Hz, 1 H, Ar), 7.72 (d, Jm=1.6 Hz, 1 H, Ar), 7.84 (m, 2H, Ar), 8.23 (d, Jo=8.2 Hz, 1 H, Ar), 10.21 (s, 1 H, NH).
Workup
- temperaturecooled in an ice bath
- customthe ice bath was removed
- customthe reaction mixture was evaporated in vacuo
- additionThe residue was treated with saturated aqueous sodium bicarbonate solution (1 mL)
- extractionextracted with chloroform (2×3 mL)
- dry with materialThe combined organic phases were dried over sodium sulfate
- customevaporated in vacuo
- customThe residue was purified by flash column chromatography (Merck silica gel 60, 40-63 μm; 40% ethyl acetate/hexanes)
Sources & evidence
- ORD record
- ord-205e89ade5344030b8329f781ba57545
- Source dataset
- uspto-grants-2011_03
- Patent number
- US07902248B2
Reaction notes
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