To obtain a new compound having selective estrogenic activity on estrogen receptor β-isoform, and useful as a therapeutic agent for diseases associated with blood estrogen level drop such as osteoporosis.
This new compound is shown by formula I (R1 is H or the like; R2 and R3 are each H or the like; (n) is 0-2), e.g. 4-hydroxy-3-(4- hydroxyphenyl)benzo[b]thiophene. The compound of formula I is obtained by the following procedure: a compound of formula II (R18 is a phenolic hydroxyl group-protecting group) (e.g. 3-methoxybenzenethiol) is reacted with a 2-bromo-4'- alkoxyacetophenone (e.g. 2-bromo-4'-methoxyacetophenone) under heating reflux in pyridine to form a compound which, in turn, is cyclized in polyphosphoric acid pref. at room temperature to 120°C to form an isomer mixture which is subsequently separated/purified by chromatography using e.g. silica gel, and as necessary, iodine is introduced onto the 2-position of the resulting purified substance followed by further introducing substituent(s) onto the substance.
OE MOROHISA
KANEKO HIDEO
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