The invention provides a process for preparing 6-alkoxy-3-(4-alkoxyphenyl)benzo[B]thiophenes in good yield on a manufacturing scale without generating a thick, potentially yield-reducing, paste. The invention also provides methods for converting a-(-alkoxyphenylthio)-4-alkoxyacetophenones into 6-hydroxy-2-(4-hydroxyphenyl)-3-[4-(2-aminoethoxy)benzoyl]benzo[B]thiophen es via acylation of a dialkoxy benzo[B]thiophene. Each of these preparations relies on an intramolecular cyclization of a dialkoxy acetophenone derivative to yield a benzo[B]thiophene without generating a thick paste that lowers overall yields on a manufacturing scale.
本发明提供了一种制备6-烷氧基-3-(4-烷氧基苯基)苯并[B]
噻吩的工艺,能够在制造规模上获得良好的收率,而不产生浓稠的可能降低产量的糊状物。本发明还提供了一种将α-(-烷氧基苯基
硫基)-4-烷氧基
乙酰苯酮转化为6-羟基-2-(
4-羟基苯基)-3-[4-(2-
氨乙氧基)苯甲酰基]苯并[B]
噻吩的方法,通过对双烷氧基苯并[B]
噻吩进行酰化。这些制备方法均依赖于双烷氧基
乙酰苯酮衍
生物的分子内环化,以产生苯并[B]
噻吩,而不会产生降低制造规模总收率的浓稠糊状物。