Sodium Hydroxide → 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

(R)-5-(2-(benzylamino)ethyl)-1-(6,8-difluorochroman-3-yl)-1H-imidazole-2(3H)-thione hydrochloride (8 g, 18.27 mmol) was dissolved in methanol (120 ml) at 40-45° C., diluted with water (18.00 ml), crystallisation occurred. The precipitate was dissolved with heating to 67-68° C. and stirring. To the solution 1N sodium hydroxide (19.18 ml, 19.18 mmol) was added dropwise during 1 hour via a syringe pump. The mixture was aged for 30 min at 67° C., cooled to 20° C. during 1 hour, aged at 20° C. for 30 min. Crystals were collected, washed with MeOH-water 1:1 (36 ml), dried to give (R)-5-(2-(benzylamino)ethyl)-1-(6,8-difluorochroman-3-yl)-1H-imidazole-2(3H)-thione (6.7 g, 16.69 mmol, 91% yield).

Provenance & Evidence