4-(4-Alkylpiperazin-1-yl)phenyl group: A novel class of basic side chains for selective estrogen receptor modulators

In the structure–activity relationships of spiro[indene-1,1′-indane] series, the 4-(4-alkylpiperazin-1-yl)phenyl group was found to be functionally equipotent to the 4-(1-piperidinoethoxy)phenyl group, the most widely used basic side chain in selective estrogen receptor modulators.