An improved process for preparing 3-(4-aminoethoxy-benzoyl)benzo beta -thiophenes
申请人:ELI LILLY AND COMPANY
公开号:EP0693488A1
公开(公告)日:1996-01-24
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]thiophenes 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.
本发明提供了一种在生产规模上以良好收率制备 6-烷氧基-3-(4-烷氧基苯基)苯并[B]噻吩的工艺,而不会产生粘稠的、可能降低收率的糊状物。本发明还提供了通过二烷氧基苯并[B]噻吩的酰化将 a-(-烷氧基苯硫基)-4-烷氧基苯乙酮转化为 6-羟基-2-(4-羟基苯基)-3-[4-(2-氨基乙氧基)-苯甲酰基]苯并[B]噻吩的方法。上述每种制备方法都依赖于二烷氧基苯乙酮衍生物的分子内环化来生成苯并[B]噻吩,而不会生成浓稠的糊状物,从而降低了生产规模上的总体产量。