THE PRESENT INVENTION RELATES TO THE USE OF THE COMPOUNDS OF GENERAL FORMULA 1 WHEREIN THE GROUPS R1, R2 AND R3 MAY HAVE THE MEANINGS SPECIFIED IN THE CLAIMS AND IN THE DESCRIPTION, FOR PREPARING A PHARMACEUTICAL COMPOSITION FOR THE TREATMENT OF RESPIRATORY COMPLAINTS, AS WELL AS NEW COMPOUNDS OF FORMULA 1, PROCESSES FOR PREPARING THEM, AND PHARMACEUTICAL FORMULATIONS CONTAINING THEM.