Methyl iodide → HCID 22031037, compound

Participants

Reaction Steps

A mixture of 1 g 6-bromoimidazo[1,2-a]pyridine-3-carboxylic acid hydrazide (compound in Production Example 276), 0.24 mL carbon disulfide, 157 mg sodium hydroxide, 15 mL ethanol and 15 mL water was heated for 5 hours under reflux. The reaction solution was poured into a mixture of iced water and an aqueous saturated ammonium chloride solution, and the precipitated crystals were collected by filtration. 1 N hydrochloric acid was added to the filtrate, and the resulting crystals were also collected by filtration. The combined crystals were dried under reduced pressure by a vacuum pump, to give 1.12 g crude product of 5-(6-bromoimidazo[1,2-a]pyridin-3-yl)[1,3,4)oxadiazole-2-thiol as pale brown crystals. 60 μL methyl iodide was added to a mixture of 258 mg of this thiol derivative, 242 mg potassium carbonate and 30 mL N,N-dimethylformamide under ice-coolingd water in a stream of nitrogen, and the mixture was stirred for 10 minutes. Ethyl acetate and water were added to the reaction solution, and the organic layer was separated. The aqueous layer was saturated with common salt and then extracted with ethyl acetate. The combined organic layer was washed twice with water and then with brine and dried over anhydrous sodium sulfate. The drying agent was filtered off, and the filtrate was evaporated. Hexane was added to the resulting residues, the crystals were collected by filtration and dried under reduced pressure with a vacuum pump. 245 mg of the title compound was obtained as pale brown crystals.

Provenance & Evidence