N-bromobutanimide → 4-(4-Amino-3-bromo-phenyl)-1,1-dioxo-hexahydro-1lambda6-thiopyran-4-carbonitrile

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Reaction Conditions

Reaction Steps

A solution of 4-(4-amino-phenyl)-1,1-dioxo-hexahydro-1λ6-thiopyran-4-carbonitrile (114 mg, 0.455 mmol, as prepared in the previous step) in CH2Cl2 (15 mL) was cooled to 0° C., treated with solid NBS (77.0 mg, 0.433 mmol), and stirred at that temperature for 30 min. The mixture was diluted with CH2Cl2 (20 mL) and washed with satd aq NaHCO3 (1×20 mL). The aqueous layer was extracted with CH2Cl2 (1×20 mL). The combined organic layers were dried over MgSO4 and concentrated in vacuo. Silica gel chromatography of the residue on a 50-g Varian MegaBond Elut SPE column with 50% EtOAc-hexane afforded the title compound (136 mg, 90%) as a white solid. 1H-NMR (CDCl3; 400 MHz): δ 7.53 (d, 1H, J=2.0 Hz), 7.23 (dd, 1H, J=8.4, 2.0 Hz), 6.79 (d, 1H, J=8.0 Hz), 4.40-4.15 (br s, 2H), 3.60-3.45 (m, 2H), 3.26-3.11 (m, 2H), 2.78-2.63 (m, 2H), 2.51-2.38 (m, 2H).

Provenance & Evidence