A solution of 0.1 mol of 1-cyclohexylamino-2-propanol in 30 grams of
chloroform was saturated with dry hydrogen chloride gas, with cooling. A
solution of 0.1 mol of benzoyl chloride in 30 grams of chloroform was added
and the solution was heated in a bath at 50° to 55°C for four days under a
reflux condenser protected from atmospheric moisture. Then the solvent was
removed by vacuum distillation while the mixture was warmed on a water
bath. Benzene was then added to the syrupy residue and the reaction product
crystallized out after the benzene was removed by vacuum distillation.
The crystallized solid residue was washed with anhydrous ether to remove any
unreacted benzoyl chloride. The 1-cyclohexylamino-2-propyl benzoate
hydrochloride obtained was purified by two recrystallizations from absolute
alcohol. It melted at 177° to 178.5°C.