The present invention relates to a novel benzopyran or thiobenzopyran derivative represented by formula (1): pharmaceutically acceptable salt or stereoisomer thereof, in which X, R
1
, R
2
, R
3
, R
4
and A are defined as described in the specification, and to a process for preparation thereof and a pharmaceutical composition having anti-estrogenic activity which contains the compound (1) as an active component.
The present invention provides novel benzopyran compounds, pharmaceutically acceptable salts thereof and stereoisomers thereof where the benzopyran compounds of the invention are compounds according to Formula I:
The present invention further provides pharmaceutical compositions which possess anti-estrogenic activity and comprise at least one benzopyran compound of the invention and a method of treating breast cancer by administration of an effective amount of a benzopyran compound provided by the present invention.