[I:1]Cl.[O:3]1[C:7]2[CH:8]=[CH:9][C:10]([S:12]([Cl:15])(=[O:14])=[O:13])=[CH:11][C:6]=2[CH2:5][CH2:4]1.C(#N)C>C(Cl)Cl>[I:1][C:8]1[C:7]2[O:3][CH2:4][CH2:5][C:6]=2[CH:11]=[C:10]([S:12]([Cl:15])(=[O:13])=[O:14])[CH:9]=1A solution of ICl (7.7 g, 47 mmol) in DCM (100 mL) was added dropwise to a solution of 2,3-dihydro-benzofuran-5-sulfonyl chloride (5 g, 23 mmol; Intermediate 54) in DCM (100 mL) at reflux temperature under nitrogen atmosphere. The reaction was heated at reflux overnight. The reaction mixture was cooled at room temperature and acetonitrile (50 mL) was added. The resultant mixture was washed with a saturated solution of NaHCO3 and the organic phase was separated followed by elimination of the volatiles under vacuum to give 8 g of brown oil which was used to the next step without further purification. 1H NMR 270 MHz (CDCl3) δ ppm 3.45 (t, J=8.91 Hz, 2H) 4.82 (t, J=8.91 Hz, 2H) 7.79 (d, J=1.48 Hz, 1H) 8.16 (d, J=1.98 Hz, 1H).
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