Compounds

A compound of the formula (I):

• R1R2N—CH2CH2—CHAr1—CH2—NR3—CO—R4 (I)
• wherein:
• R1 is hydrogen, C1-6alkyl, C2-6alkenyl, aryl, C1-6alkanoyl, C1-6alkoxycarbonyl or arylcarbonyl;
• any of such groups being optionally substituted;
• R2 is hydrogen or C1-6alkyl;
• or R1 or R2 are joined to form an optionally substituted morpholino ring;
• Ar1 is phenyl mono- or di-substituted by halo;
• R3 is hydrogen or C1-6alkyl;
• R4 is optionally substituted naphth-1-yl;
• or
• pharmaceutically acceptable salts thereof.