Benzo(d)thiazol-2-amine → (2E)-N-(1,3-benzothiazol-2-yl)-2-cyclopentyloxyimino-2-(4-methylsulfonylphenyl)acetamide

Temperature

0 °C

(E)-Cyclopentyloxyimino-(4-methanesulfonyl-phenyl)-acetic acid (37 mg, 0.12 mmol), N,N-diisopropylethylamine (92 μL, 0.53 mmol) and 2-aminobenzothiazole (27 mg, 0.18 mmol) were combined in methylene chloride (2 mL) and cooled to 0° C. O-(7-Azabenzotriazole-1-yl)-N,N,N′N′-tetramethyluronium hexafluorophosphate (67 mg, 0.18 mmol) was added and the cooling bath was removed. After stirring 16 h, the reaction mixture was diluted with chloroform (2 mL) and washed with saturated aqueous sodium bicarbonate solution (1.5 mL). The aqueous phase was extracted with chloroform (1.5 mL) and the combined organic phases were filtered through 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-cyclopentyloxyimino-2-(4-methanesulfonyl-phenyl)-acetamide (34 mg, 43%) as a white solid: LC-MS (ESI) m/e calcd for C21H21N3O4S2 [M+] 443.10, found 444 [M+H+]; H1-NMR (400 MHz, CDCl3) δ ppm 1.66 (m, 4 H, 2×CH2), 1.90 (m, 4 H, 2×CH2), 3.11 (s, 3 H, SO2CH3), 4.95 (m, 1 H, OCH), 7.35 (brt, 1 H, Ar), 7.48 (brt, 1 H, Ar), 7.72 (d, J=8.4 Hz, 2 H, Ar), 7.83 (m, 2H, Ar), 8.03 (d, J=8.4 Hz, 2 H, Ar), 10.24 (s, 1 H, NH).

1. customthe cooling bath was removed
2. additionthe reaction mixture was diluted with chloroform (2 mL)
3. washwashed with saturated aqueous sodium bicarbonate solution (1.5 mL)
4. extractionThe aqueous phase was extracted with chloroform (1.5 mL)
5. filtrationthe combined organic phases were filtered through sodium sulfate
6. customevaporated in vacuo
7. customThe residue was purified by flash column chromatography (Merck silica gel 60, 40-63 μm; 40% ethyl acetate/hexanes)

ORD record

ord-c30da581484846b5b77fce67e5484036

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07902248B2