A subject of the present application is new derivatives of 4-aminopiperidines of formula ##STR00001## in which R.sub.1, R.sub.2 and R.sub.3 represent various radical, and their preparation processes by synthetic methods in parallel in liquid and solid phase. These products having a good affinity with certain sub-types of somatostatin receptors, they are particularly useful for treating the pathological states or diseases in which one (or more) somatostatin receptors are involved.