Sulfated benzimidazolone derivatives having mixed serotonin receptor affinity

1. A compound of formula (I)

wherein

R 1 , R 2 , R 3 , and R 4 are each hydrogen or sulfate monoester with the proviso that R 1 , R 2 , R 3 , and R 4 cannot simultaneously be hydrogen, or a pharmacologically acceptable salt thereof.

2. The compounds of formula (I) according to claim 1 wherein two or three of the four radicals R 1 , R 2 , R 3 , and R 4 are hydrogen.

3. The compound according to claim 1 , selected from the group consisting of;

or a pharmacologically acceptable salt thereof.

4. A process for the preparation of a compound of formula (I) according to

one of claims 1 to 3 , wherein a compound of formula (II)

wherein R 1 , R 2 , R 3 and R 4 are each hydroxy or hydrogen and at least one among R 1 , R 2 , R 3 and R 4 is hydroxy, is reacted with a sulfation reagent.

5. A process for the preparation of compound of formula (I) according to one of claims 1 to 3 , wherein a compound of formula (III)

wherein R 1 , R 2 , R 3 , and R 4 are each a protected sulfate monoester or hydrogen and at least one among R 1 , R 2 , R 3 , and R 4 is a protected sulfate monoester, is reacted with a cleavage reagent to restore the free acid moiety of the sulfate monoester group.

6. A pharmaceutical composition comprising a compound of formula (I) according to one of claims 1 to 3 , or a pharmacologically acceptable salt thereof, in admixture with one or more pharmaceutical carriers, diluents or excipients.