Phenyl thioxochloroformate → 4-[1-(2,3-dichlorophenyl)ethyl]-1,3-dihydroimidazole-2-thione

Participants

Reaction Steps

A 1:1 mixture of 4-[1-(2,3-dichloro-phenyl)-ethyl]-1H-imidazole (Intermediate A4), and 4-[1-(2,3-dichloro-phenyl)-vinyl]-1H-imidazole (Intermediate A3) (0.77 g, 3.2 mmol) in tetrahydrofuran (THF) (10 mL) and water (10 mL) was treated with NaHCO3 (1.64 g, 19.5 mmol) at rt for 10 m. Phenyl chlorothionoformate (1.1 mL, 7.95 mmol) was added and stirring was continued for 5 h. The mixture was diluted with water and extracted with hexane:ethyl acetate (3×). The organic portions were combined, dried over MgSO4, filtered and the solvent was removed under vacuum. The residue was dissolved in MeOH (20 mL) and treated with triethylamine (NEt3) (1 mL) for 18 h at rt. The mixture was concentrated onto silica gel. The material was purified by elution from silica gel with 1 to 2% MeOH: CH2Cl2. The solids were titurated with CHCl3: hexanes and collected on a glass frit to give a white solid 4-[1-(2,3-dichloro-phenyl)-ethyl]-1,3-dihydro-imidazole-2-thione (Compound 1) 40 mg.

Provenance & Evidence