Hydrochloric Acid → Ethyl 4-(3-piperidinomethylphenoxy)butyrimidate

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Reaction Steps

An ice-cold solution of 4-(3-piperidinomethylphenoxy)butyronitrile (0.9 g) prepared as described in Example 17 in a mixture of ethanol (5 ml) and dioxan (5 ml) was saturated with hydrogen chloride gas. The mixture was left for 16 hours during which time the temperature rose to ambient. The solvent was then removed by evaporation to yield a hydrochloride salt of ethyl 4-(3-piperidinomethylphenoxy)butyrimidate as a colourless oil. The imidate salt was mixed with 4-methylcarbamoylmethyl-o-phenylenediamine (0.6 g) prepared as described in Example 8 and ethanol (38 ml) and the mixture was heated under reflux for 41/2 hours. The solvent was removed by evaporation in vacuo and the residue dissolved in water. The aqueous solution was washed with ethyl acetate and then aqueous ammonia solution (S.G. 0.880) was added until the solution was alkaline. The solution was extracted with ethyl acetate and the extracts were washed and dried. Partial removal of the ethyl acetate caused crystallisation of 5-methylcarbamoylmethyl-2-[3-(3-piperidinomethylphenoxy)propyl]benzimidazole (m.p. 111°-115° C.) as colourless crystals. [Formula I E=--(CH2)3.O, J is hydrogen, R1 =methyl, R2 =H, NR3R4 =piperidino, m=1, and p=1].

Provenance & Evidence