Bi-aryl or aryl-heteroaryl substituted indoles

A compound of formula (I) or a pharmaceutically acceptable salt thereof:

• in which
• X is O or S;
• R1 is NHCOR6;
• R2 is hydrogen, halogen, or C1-7alkyl;
• R3 is phenyl, which is substituted by phenyl;
• or phenyl, which is substituted by a 5-membered heteroaryl group;
• R6 is a hydrogen atom, or C1-6alkyl;
• Provided that:
• R3 cannot be 4-phenyl-1,3-thiazol-2-yl.