Ammonium Chloride → HCID 86702158, compound

Participants

Reaction Steps

To a solution of 2-(2,4-dimethoxybenzyl)-5-fluoroisothiazolidine-1,1-dioxide (5.700 g, 19.7 mmol) in anhydrous tetrahydrofuran (225 mL), cooled to −78° C., was slowly added n-butyl lithium (14.973 mL of a 2.5 N solution in hexanes, 37.4 mmol) and the resulting dark orange/red solution stirred for 1 hr. A solution of N-fluorobenzene sulfonamide (14.6 g, 46.3 mmol) in anhydrous tetrahydrofuran (60 mL) was added slowly over 30 mins, stirring at −78° C. for 3 hrs and at room temperature for 2.5 hrs. The reaction was poured into saturated aqueous ammonium chloride, diluted with ethyl acetate, and the organic layer isolated. The organic layer was washed with saturated aqueous sodium chloride, dried (anhydrous sodium sulfate), filtered, and concentrated in vacuo. The crude material was suspended in methylene chloride and filtered through a pad of silica gel, washing with methylene chloride, and concentrating the solution. The crude material was purified by silica gel chromatography (20-75% ethyl acetate/hexanes) and then by preparative HPLC (C18, 32-95% acetonitrile/water over 17 mins) to give a tan oil (0.106 g, 2%). 1H NMR (CDCl3, 300 MHz) δ 7.21-7.18 (d, 1H, J=8.4 Hz), 6.49-6.45 (m, 2H), 4.28 (s, 2H), 3.82 (s, 3H), 3.14 (s, 3H), 3.19-3.15 (m, 2H), 2.70-2.55 (m, 2H).

Provenance & Evidence