Hydantoin derivatives with affinity for somatostatin receptors

A compounds of formula I

• wherein
• X and Y independently are O or H, H,
• R1 is a group of formula
• wherein the Ra independently are hydrogen, C1-4 alkyl or a CH3COO—CH(CH3)OCO-group and Z is a saturated or unsaturated aliphatic C2-6 hydrocarbonic chain which is (a) optionally interrupted by —O— or —S— and (b) optionally substituted by C1-4 alkyl or C1-4 alkoxy groups,
• R2 is a group of formula —SO2—Ar or —CH2—Ar wherein Ar is phenyl or naphthyl optionally mono- or di- substituted by hydroxy, halogen, C1-4 alkyl, C1-4 alkoxy, cyano, trifluoromethyl, aminomethyl, dimethylaminocarbonyl, benzimidazolyloxy or morpholinocarbonyl, or by a group of formula
• wherein Q is CH2, O, S or CO, the Rb independently are hydrogen, C1-4alkyl, C1-4alkoxy, amino, halogen, hydroxy, a NH2—(CH2)4—CH(NH2)—COO— group or form together a methylenedioxy, and the Rc independently are hydrogen or C1-4 alkyl,
• R3 is hydrogen or C1-4 alkyl and
• R4 is a group of formula
• wherein Rd is hydrogen, halogen, C1-4 alkyl or C1-4alkoxy, and Re is hydrogen, C1-4alkyl or benzyl,
• in free base or acid addition salt form.