Methyl iodide → 1-Isopropyl-2-methylsulfanyl-1H-imidazole-4,5-dione

Participants

Reaction Steps

Isopropyl thiourea 9 (8.0 g, 67.7 mmol) in 100 ml of dry acetone was added iodomethane (6.3 ml, 101 mmol) dropwise at room temperature. After the addition was completed, the mixture was refluxed for 1 hour, and the solvent was evaporated to dryness under the reduced pressure to give a gum. The gummy hydroiodide salt was suspended in 200 ml of dry methylene chloride and to the suspension was added triethylamine (37.7 ml, 270 mmol). The mixture was stirred for 30 minutes at room temperature, cooled down to −78° C. with a dry ice/acetone bath. To the mixture was added dropwise oxalyl chloride (40.6 ml of 2M solution, 81.2 mmol) and stirred at −78° C. for 1 hour. The reaction was quenched by addition of water to decompose the excess oxalyl chloride, the solvent was dried over Na2SO4 and evaporated to dryness in vacuo.

Provenance & Evidence