In order to examine the structure and stability relationship of secondary amine of aminoalkylesters, derivatives of [(C6H5)(m-CH3O-C6H4) CHCOOCH2CH2NHR3] were synthesized, changing R3 to CH3 (I), C2H5 (II), n-C3H7 (III), iso-C3H7 (IV), n-C4H9 (V) and CH2C6H5 (VII). With the use of a protonated amine ester as a reaction species, catalytic constants of hydrogen ion (kH) and hydroxyl ion (kOH) were determined. The substituent effect on kH and kOH was explained with Taft Es values, and the case in which an unprotonated amine ester was taken as being hydrolyzed spontaneously was discussed briefly.
