4-Chlorophenyl Isocyanate → HCID 19807345, compound

To a solution of 5-bromobenzo[B]thiophene (9.4 mmol) in 100 mL of anhydrous tetrahydrofuran under a nitrogen atmosphere at -78° C. was added 5.9 mL of a 1.6 M hexanes solution of n-butyllithium (9.4 mmol). The 5bromobenzo[B]thiophene was synthesized by procedures well known in the art. See, European Patent Application 355827 (published Feb. 28, 1990). The reaction was warmed to 0° C. and stirred for 30 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 50 mL of water. Sodium acetate (74 mmol) and hydroxylamine-0-sulphonic acid (24 mmol) were added to this solution and this reaction was stirred at room temperature for 1.5 hours. This mixture was diluted with 50 mL of water and the reaction extracted with ether (3×50 mL). The combined organic layer was extracted with 1 N sodium hydroxide (3×50 mL), the organic layer discarded, and the aqueous layer acidified with about 150 mL of 1 N hydrochloric acid. The aqueous layer was extracted with methylene chloride (3×50 mL). The combined organic layer was dried with anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by flash chromatography with 30% acetone in hexanes with 1% acetic acid on silica gel to obtain 340 mg of 5benzo[B]thiophenesulfonamide. The sulfonamide (1.6 mmol) was reacted with 4-chlorophenylisocyanate (1.9 mmol) as described in Method A above to obtain 240 mg of the title product as a solid. 1H NMR (CD3SOCD3): δ9.04 (s, 1 H), 8.16 (s, 1 H), 8.08 (d, J =6 Hz, 1 H), 8.04 (d, J =6 Hz, 1 H), 7.52 (d, J =6 Hz, H), 7.46 (m, 2 H), 7.42 (d, J =9 Hz, 2 H), 7.30 (d, J =Hz, 2 H).

ORD record

ord-156eabc69de6437f95f01251bcc6b957

Source dataset

uspto-grants-1992_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05169860