Sulfur Dioxide → HCID 22504018, compound

Participants

Reaction Conditions

Reaction Steps

To a −10° C. (acetone/ice/sodium chloride) CH2Cl2 solution of 4-fluoro-2-(2-naphthalen-1-yl-ethoxy)-phenylamine (15.0 g, 53.30 mmol) was added boron trifluoride diethyl etherate (19.7 mL, 160.0 mmol) dropwise. Tert-Butyl nitrite (8.30 mL, 69.3 mmol) was then slowly added dropwise. The reaction mixture was allowed to stirred at −10° C. for 30 min. Chilled pentane (150 mL) was then added to precipitate the diazo-salt from CH2Cl2. The diazo-salt was then dissolved in dioxane:acetonitrile (3:1, 150 mL) kept at 0° C. In a three-necked flask to a solution of dioxane (150 mL) and acetic acid (150 mL) at −10° C. was added copper (I) chloride (1.60 g, 16.0 mmol) and LiCl (33.0 g, 319 mmol). Sulfur dioxide (˜100 mL) was then condensed into this solution using a −78° C. cold finger. The above diazo-salt solution was then poured into this solution. The reaction was kept at 0° C. for 2 h and then placed into a preheated oil bath at 65° C. for 12 h. The reaction was then cooled and poured into EtOAc (500 mL) and washed with water, and 1 N sodium hydroxide. The organic layer was then dried (MgSO4), filtered and concentrated under reduced pressure to yield 4-fluoro-2-(2-naphthalen-1-yl-ethoxy)-benzenesulfonyl chloride as a yellowish foam (19.90 g, 98%). 1H NMR (CDCl3, 400 MHz) 8.05 (d, 1H), 7.90 (d, 1H), 7.87 (d, 1H), 7.78 (d, 1H), 7.60-6.42 (m, 4H), 6.78-6.64 (m, 2H), 4.21 (t, 2H), 3.79 (t, 2H).

Provenance & Evidence