New 14-disubstituted piperazines which can be used as medicaments and which correspond to the formula: in which R D and -A-B- have the meanings defined in the description in the racemic and optically active forms and their physiologically tolerable acid addition salts. These compounds and their physiologically tolerable salts can be used in therapeutics.

The invention relates to a process for the preparation of the compound of formula I: ##STR1## characterized in that 234-trimethoxybenzaldehyde is dissolved with piperazine and then the reaction medium is subjected to the action of hydrogen to give the compound of formula I.

Process for the preparation of the compound of formula I:characterised in that 234-trimethoxybenzaldehyde is dissolved with piperazine and the reaction mixture is then subjected to the action of hydrogen to form the compound of formula I.

Procédé de synthèse industrielle du perindopril caractérisé en ce que l'on condense l'acide perhydroindole carboxylique - 2 (2S 3aS 7aS) après protection du groupement carboxyle avec la N - [(S) carbéthoxy - 1 butyl] - (S) alanine le produit résultant de la condensation étant ensuite soumis à déprotection du carboxyle porté par l'hétérocycle. L'acide perhydroindole carboxylique - 2 (2S 3aS 7aS) et la N - [(S) carbéthoxy - 1 butyl] - (S) alanine sont eux-mêmes obtenus dans d'excellentes condition...