Ethanol → 6-(3-Nitro-phenyl)-3H-benzothiazol-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 6-bromo-2-benzothiazolinone (5.0 g, 21.7 mmol), 3-nitrophenyl boronic acid (5.0 g, 30.0 mmol), tetrakis(triphenylphosphine)-palladium (0) (1.73 g, 1.5 mmol), and potassium carbonate (8.0 g, 58.0 mmol) in toluene (100 mL), H2O (20 mL), and ethanol (30 mL) was subject to a blanket of nitrogen for 15 minutes at 50° C. and then was heated at 85° C. for 24 hours. The reaction mixture was cooled to room temperature and ethyl acetate (100 mL) was added. The organic layer was washed with aqueous ammonium chloride (2×50 mL) and with brine (100 mL), dried over magnesium sulfate and concentrated. The residue was purified via chromatography (silica gel, 25% ethyl acetate/hexane) to give 6-(3-nitro-phenyl)-3H-benzothiazol-2-one as a brown solid (0.1 g, 1 8%): mp 276-277° C.; 1H-NMR (DMSO-d)6 δ11 (s, 1H), 8.44 (t, 1H, J=2.7 Hz), 8.21-8.08 (m, 3H), 7.78-7.69 (m, 2H), 7.24 (d, 1H, J=9.23 Hz); MS (ES) m/z 271 ([M−H]−, 100%); Anal. Calc. For C13H8N2O3S.0.25 H2O: C, 56.41; H, 3.10; N, 10.12. Found: C, 56.48; H, 3.11; N, 9.99.

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