Process for the preparation of pyrroline derivatives

This invention relates to a process for the preparation of a compound, or its solvate or salt, having the formula I: in which A is or p is 1, 2 or 3, ROC- is an acyl group linked to the nitrogen atom of group A in which group R contains a substituted or unsubstituted aromatic or aromatic heterocyclic ring, R1 and R2 are substituents at identical or different carbon atoms and are separately hydrogen or C1-6 alkyl, Ra is a substituted or unsubstituted heterocyclic or aromatic carbocyclic ring. This compound is useful in the treatment of pain, hyponatraemic diseases or cerebral ischaemia. The process mentioned comprises e.g. the reaction of a compound of formula III: where A' is A or a group which is convertible into A, with a compound of formula R'COOH or its active derivative, in which R' is R or a group convertible into R.