The invention provides a compound of formula (I) or a pharmaceutically acceptable ester, amide, solvate or salt thereof, including a salt of such an ester or amide, and a solvate of such an ester, amide or salt. The invention also provides also provides the use of such compounds in the treatment or prophylaxis of a condition associated with a disease or disorder associated with estrogen receptor activity, wherein R1, R2, R3, R4, R5, R6, R7, R8,R9, R10 and R11 are as defined in the specification.
