Benzaldehyde → 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 Steps

A 250 L reactor was charged with 12.25 kg of (R)-5-(2-aminoethyl)-1-(6,8-difluorochroman-3-yl)-1H-imidazole-2(3H)-thione hydrochloride, 114.82 kg of 2-propanol was added and the mixture was stirred at maximum speed (140 rpm). Through a dropping funnel 1.856 kg of benzaldehyde was added followed by 3.945 kg of sodium triacetoxyborohydride in five portions at Ti=20-25° C. according to the following addition order:

Provenance & Evidence