A benzothiophene compound represented by a formula: ##STR1## wherein R.sup.1 represents a lower alkyl group, and R.sup.2 represents a halogen atom; a lower alkyl group; or a cycloalkyl group or cycloalkenyl group which may optionally be substituted with a lower alkyl group, a hydroxy group, an acyloxy group or an oxo group,which is a useful intermediate for synthesizing a 2-sub-stituted-3-(4-substituted benzoyl)-6-hydroxybenzo[b]-thiophene derivative having an antiestrogenic activity can be produced in an industrially advantageous manner by subjecting a compound represented by a formula: ##STR2## to a ring-closing reaction. Further, the novel compound of the formula (II) described above is a useful intermediate in the process of the present invention.