Synthesis and structure--activity relationship of a pyrimido[4,5-d]pyrimidine derivative with antidepressant activity.

The synthesis and antidepressant properties of a new pyrimido[4,5-d]pyrimidine are described. Spectral data determined in solution and in the solid state allowed establishment of the relationship between the activity and the conformation of the molecule. The spatial structure seems to be in accordance with a possible binding at the presynaptic alpha-receptor sites.