3-Chlorobenzoic Acid → 4-[6-(4-Fluorophenyl)spiro[2.4]hepta-4,6-dien-5-yl]benzenesulfonamide

Participants

Reaction Steps

A solution of 300 mg (0.88. mmol) of 4-[6-(4-fluorophenyl)spiro[2.4]hept-5-en-5-yl]benzenesulfonamide (from Step 1) in 5 mL of dichloromethane was treated with 300 mg (55% peroxyacid, 0.96 mmol) of m-chloroperoxybenzoic acid (MCPBA). The reaction was stirred at ambient temperature for 2.5 hours, washed with aqueous saturated sodium bisulfite, dried (MgSO4), and concentrated in vacuo to give a mixture of desired expoxide intermediate and m-chlorobenzoic acid; this crude mixture in 6 mL of acetic acid and 0.6 mL of water was subsequently treated with 300 mg (3.7 mmol) of sodium acetate and stirred at 80° C. for 10 hours. The reaction mixture was cooled to ambient temperature and concentrated in vacuo. The residue was partitioned between water and ethyl acetate; the organic phase was washed with aqueous saturated sodium bicarbonate, water, brine, dried (MgSO4), and reconcentrated in vacuo. Purification by silica gel chromatography gave 118 mg (39%) of 4-[6-(4-fluorophenyl)spiro[2.4]hepta-4,6-dien-5-yl]benzenesulfonamide as a colorless solid: mp 110°-116° C. (dec); NMR (CDCl3) δ 1.80 (s, 4H), 4.81 (br s, 2H), 6.21 (d, J=2 Hz, 1H), 6.33 (d, J=2 Hz, 1H), 6.94 (t, J=9 HZ, 2H), 7.06-7.15 (m, 2H), 7.29 d, J=8 Hz, 2H), 7.78 (d, J=8 Hz, 2H),

Provenance & Evidence