Hydrochloric Acid → Isoquinoline-6-sulfonyl chloride

Participants

Reaction Steps

4.0 g of 6-aminoisoquinoline (Reference Compound 1) was suspended at 0° C. in 40 mL of concentrated hydrochloric acid (35%). To the suspension, 4.0 g of sodium nitrite was added in small portions, and the mixture was stirred for 30 minutes. This reaction solution was added dropwise at 0° C. to a mixed solution of 20 mL of acetic acid saturated with sulfite gas generated from sodium bisulfite and sulfuric acid, and 298 mg of copper chloride, and the mixture was stirred for 1 hour. The mixture was neutralized by the addition of a saturated aqueous solution of sodium bicarbonate, followed by extraction with dichloromethane (100 mL×2). The organic layer was washed with saturated saline and then dried over anhydrous sodium sulfate. The obtained dichloromethane solution was used in the next reaction without being further purified because the compound of interest was unstable.

Provenance & Evidence