4-Chlorophenyl Isocyanate → HCID 67880457, compound

Participants

Reaction Steps

To a solution of 5-bromobenzofuran (4.7 g, 23.8 mmol),dissolved in 100 mL of anhydrous tetrahydrofuran at -78° C. under a nitrogen atmosphere, was added 15.0 mL of a 1.6 M hexanes solution of n-butyllithium (23.8 mmol). The reaction was warmed to 0° C. and stirred for 15 minutes. Sulfur dioxide gas was bubbled through this mixture for 20 minutes at 0° C. and the reaction concentrated under vacuum. The residue was dissolved in 250 mL of water. To this solution were added 15.6 g (190 mmol) of sodium acetate and 8.3 g (73.7 mmol) of hydroxylamine-0-sulphonic acid. This reaction was stirred at room temperature for 1.5 hours. The solution was extracted with diethyl ether (2×150 mL). The combined organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated under vacuum. Flash chromatography of the residue with 18% ethyl acetate/hexanes on silica gel provided 2.3 g (10.0 mmol) of 5-benzofuransulfonamide. The 5-benzofuransulfonamide was reacted with 4-chlorophenylisocyanate (10.0 mmol), as described in Method A above, to obtain 1.4 g of the title product as a solid. 1H NMR (CD3SOCD3): δ0.62 (bs, 1 H), 9.02 (s, 1 H), 8.38 (d, J =2 Hz, 1 H), 8.20 (d, J =2Hz, 1 H), 7.96 (dd, J =2, 9 Hz, 1 H), 7.86 (d, J =9 Hz, 1 H), 7.38 (d, J =9 Hz, 2 H), 7.30 (d, J =9 Hz, 2 H), 7.20 (d, J =2 Hz, 1 H).

Provenance & Evidence