Water → 1-[3-(Piperidin-1-yl)propyl]-1H-benzimidazol-2-amine

Participants

Reaction Steps

To a stirred suspension of 20.0 g. (0.086 mole) of N-[3-(1-piperidinyl)propyl]-o-phenylenediamine in 80 ml. water, 20 ml. of isopropanol was added to obtain a homogenous solution. With continued stirring, 21.2 g. (0.200 mole) of cyanogen bromide was added in portions over a one hour period. Room temperature was maintained throughout the addition. After stirring for an additional 2 hours the reaction mixture was allowed to stand overnight. The mixture was then poured into ice-water, made strongly alkaline with KOH and extracted with methylene chloride. The extracts were evaporated to a red oil which crystallized from ether, 7.9 g. (36% yield), m.p. 176°-178° C. An analytical sample of 1-[3-(1-piperidinyl)propyl]-2-amino benzimidazole was obtained by crystallization from benzene-cyclohexane, m.p. 179°-181° C.

Provenance & Evidence