PURPOSE: To obtain an optically active substance of the titled compound useful as an optically resolving agent in high purity in high yield easily, by crystallizing preferentially an optically active p-hydroxybenzoate from a solution of a p-hydroxybenzoate of α-p-tolylethylamine.

CONSTITUTION: A salt of (±)-α-p-tolylethylamine of α-p-tolylethylamine containing an excess of one of the optically active forms of it and p-hydroxybenzoic acid is dissolved in a liquid diluent under heating to give a supersaturated solution. A small amount of optical active salt of α-p-tolylethylamine and p- hydroxybenzoate is seeded to the supersaturated solution, and the same optically active salt as the seeded optically active salt is crystallized and separated to give the desired compound. Methanol or ethanol may be cited as the liquid duluent. This process shows buffer actuon on crystallization pressure of antipode, and always keeps a crystallization solution and a crystal phase in a stabilized phase equilibrium relationship.