Water → 1-((3R)-6,8-Difluoro-3,4-dihydro-2H-1-benzopyran-3-yl)-1,3-dihydro-5-(2-((phenylmethyl)amino)ethyl)-2H-imidazole-2-thione

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)—N-benzyl-N-(2-(3-(6,8-difluorochroman-3-yl)-2-thioxo-2,3-dihydro-1H-imidazol-4-yl)ethyl)-2-nitrobenzenesulfonamide (compound K′, 8 g, 13.64 mmol) and 2-mercaptoacetic acid (2.84 ml, 40.9 mmol) in dimethylformamide (DMF) (80 ml) was added 10N potassium hydroxide (10.23 ml, 102 mmol) in one portion with water cooling and the mixture was stirred at 20-25° C. under HPLC control for 3 hours. Methanol-water 1:1 (160 ml) was slowly added with stirring, the mixture was stirred for 2 hours at 20-25° C. Precipitate was collected, washed with MeOH-water 1:1 (80 ml), dried to give (R)-5-(2-(benzylamino)ethyl)-1-(6,8-difluorochroman-3-yl)-1H-imidazole-2(3H)-thione (4.96 g, 12.35 mmol, 91% yield).

Provenance & Evidence