Process and intermediates for production of 7-substituted antiestrogens

A process for preparing an intermediate compound of formula (II) where X is as defined in the specification, R 1 is haloalkyl, alkyl, alkenyl, cycloalkyl, carboxyalkyl, alkoxycarbonylalkyl, aryl or arylalkyl; R 2 , R 3 , R 4 and R 5 are organic groups as defined in the specification, which process comprises aromatisation of a compound of formula (III) where R 1 , R 2 , R 3 , n, X and R 5 are as defined in relation to formula (II) and R 4' is a group R 4 or a precursor group thereof, and thereafter if necessary or desired, carrying out one or more of the following steps: (i) removing any hydroxy protecting groups R; (ii) converting a precursor group R 4 ' to a group R 4 , or where R 4 ' is a group R 4 , converting it to a different such group. Compounds obtained are useful intermediates for example in the preparation of fulvestrant. Novel intermediates are also claimed.