Thionyl Chloride → 6-Chloro-1-(5-isothiazolyl)-3,4-dihydronaphthalene

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Reaction Steps

0.072 ml of thionyl chloride is added at room temperature to a solution of 132 mg of 6-chloro-1-hydroxy-1-(5-isothiazolyl)-1,2,3,4-tetrahydronaphthalene (Example 12) in 0.45 ml of benzene, and the mixture is then stirred at 75° for 1.5 hours. The mixture is concentrated under reduced pressure, 0.156 ml of morpholine is added to the resulting resin, and the mixture is stirred at 75° for 2.5 hours. The black suspension is cooled to 2° and treated with 5N HCl which has likewise been pre-cooled. The pH is then adjusted to 8 with solid NaHCO3 and extraction is carried out with chloroform. The organic phase is separated off, dried over sodium sulfate and concentrated. The crude title compound is purified by column chromatography (SiO2, hexane/ethyl acetate 4:1 ) and crystallisation from hexane; 1H-NMR (CDCl3): δ (ppm)=2.44 (m,2H), 2.85 (m,2H), 6.37 (t,1H), 7.14 (m,2H), 7.19 (d,1H), 7.21 (s,1H), 8.49 (d,1H).

Provenance & Evidence