Ammonia → HCID 67546981, compound

Participants

Reaction Steps

A mixture of 2-(5-chlorothiophen-3-yl)-5-ethyl-4-(3-pyridyl)-imidazole (2.00 g) in chlorosulfonic acid (15 ml) was stirred at room temperature for one week. The mixture was slowly added dropwise to 28% aqueous ammonia (500 ml), and the resulting mixture was stirred for 30 minutes and then concentrated under reduced pressure. The resulting residue was dissolved in methanol-tetrahydrofuran (5:1), dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The residue was purified by silica gel flush column chromatography (solvent: chloroform:methanol=10:1→2.5:1), and then, by NH silica gel flush column chromatography (solvent: chloroform:methanol=10:1→4:1) to obtain 2-(5-chloro-2-sulfothiophen-3-yl)-5-ethyl-4-(3-pyridyl)imidazole and 2-(5-chloro-2-sulfamoylthiophen-3-yl)-5-ethyl-4-(3-pyridyl)imidazole. Each product was treated with hydrogen chloride-dioxane solution to obtain 2-(5-chloro-2-sulfothiophen-3-yl)-5-ethyl-4-(3-pyridyl)imidazole dihydrochloride (741 mg) and 2-(5-chloro-2-sulfamoylthiophen-3-yl)-5-ethyl-4-(3-pyridyl)imidazole dihydrochloride (105 mg) each as colorless powder.

Provenance & Evidence