p-Toluenesulfonic acid → ethyl 4-[[1-[(4-fluorophenyl)methyl]-1H-benzimidazol-2-yl]amino]hexahydro-1H-azepine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 33.3 parts of ethyl hexahydro-4-oxo-1H-azepine-1-carboxylate, 36.15 parts of 1-(4-fluorophenylmethyl)-1H-benzimidazol-2-amine, 320 parts of methylbenzene and 0.1 parts of 4-methylbenzenesulfonic acid was stirred overnight at reflux temperature using a water separator. After cooling to 50° C., 80 parts of ethanol were added. 4.2 Parts of sodium tetrahydroborate were added portionwise and upon completion, stirring was continued for 2 hours at 50° C. After cooling, water and 4.8 parts of methanol were added while stirring. The layers were separated and the aqueous layer was extracted with methylbenzene. The combined organic layers were dried, filtered and evaporated, yielding 73 parts (100%) of ethyl 4-[[1-[(4-fluorophenyl)methyl]-1H-benzimidazol-2-yl]amino]hexahydro-1H-azepine-1-carboxylate as a residue (compound 20).

Provenance & Evidence