168102-05-4Relevant articles and documents
Practical synthesis of ethyl 3-fluoro-1-pyrrole-2-carboxylate: A key fragment of a potent drug candidate against hepatitis b virus
René, Adeline,Quilan, Maxime,Deng, Yicheng,Cheng, Yang,Teleha, Christopher A.,Raboisson, Pierre,Bonfanti, Jean-Fran?ois,Fortin, Jér?me,Charette, André. B.,Pannecoucke, Xavier,Poisson, Thomas,Jubault, Philippe
, p. 792 - 801 (2019/10/16)
We report herein the development of two efficient synthetic routes for the preparation of a key fragment required for the synthesis of potent drug candidates of Hepatitis B virus. The ethyl 3-fluoro-1-H-pyrrole-2-carboxylate scaffold was synthesized from readily available starting materials in good overall yields. The scalability of one of the developed routes was demonstrated and afforded the desired target in good yield and excellent purity (99%).
δ,ε-Unsaturated β,β-Difluoro-α-keto Esters: Novel Synthesis and Utility as Precursors of β,β-Difluoro-α-amino Acids
Shi, Guo-qiang,Cai, Wei-ling
, p. 6289 - 6295 (2007/10/03)
Treatment of the hemiketals 6 formed from ethyl trifluoropyruvate and primary allylic alcohols with SOCl2 and pyridine readily afforded a number of α-chloro-β,β-trifluorolactyl allyl ethers 2.Subsequent reductive dechlorofluorination from 2 led to the formation of allyl-substituted difluoroenol pyruvyl ethers 3 whose Claisen rearrangement provided a convenient access to a variety of δ,ε-unsaturated β,β-difluoro-α-keto esters 4.As further transformation, direct conversion of β,β-difluoro-α-keto esters to the corresponding β,β-difluoro-α-amino acids was achieved by reductive amination of the corresponding α-keto acids with NH3*H2O/NaBH4.Furthermore, use of the prepared β,β-difluoro-α-keto ester 4a as a common precursor of other structurally related β,β-difluoro-α-amino acids was demonstrated by the synthesis of β,β-difluoroproline (18) and β,β-difluoroglutamic acid (23) through synthetic elaboration of its inherent double bond.
