The preparative synthetic approach to α,α-difluoro-γ-aminobutyric acid

Authors

DOI:

https://doi.org/10.24959/ophcj.20.209030

Keywords:

fluorine, ethyl bromodifluoroacetate, γ-aminobutyric acid, addition reaction, Curtius rearrangement

Abstract

Aim. To develop a convenient synthetic approach for the preparation of multigram amounts of 2,2-difluoro-γ-aminobutyric acid, which is pharmacologically promising analog of γ-aminobutyric acid (GABA).

Results and discussion. α,α-Difluoro-γ-aminobutyric acid (2,2-difluoro-GABA, 53 g) has been synthesized using the reaction of ethyl bromodifluoroacetate (EBDFA) addition to benzyl acrylate in the presence of copper as a key stage.

Experimental part. The reaction of EBDFA with benzyl acrylate in the presence of copper and tetramethylethylenediamine (TMEDA) was carried out; the resulting product was transformed to the target α,α-difluoro-γ-aminobutyric acid (in the form of hydrochloride) by consecutive debenzylation, Curtius rearrangement and treatment with hydrochloric acid to remove protecting groups. The synthesis was scaled up for the preparation of 53 g of α,α-difluoro-γ-aminobutyric acid. The ethyl ester of α,α-difluoro-γ-aminobutyric acid was also prepared and further transformed to 3,3-difluoropyrrolidine-2-one. The structure of the compounds synthesized was confirmed by 1Н, 13C and 19F NMR spectroscopy, mass spectrometry and elemental analysis.

Conclusions. It has been shown that the synthetic approach developed can be used for the preparation of α,α-difluoro-γ-aminobutyric acid in multigram amounts. The pathway is much more convenient, cheaper and safer compared to the method earlier described.

Received: 30.07.2020

Revised: 19.08.2020

Accepted: 27.08.2020

Supporting Agencies

  • NASU theme «Synthesis of new fluoro- and phosphorus containing acyclic and heterocyclic analogues of natural compounds» (state registration № 0119U100611
  • 2019 – 2021 years)

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Published

2020-09-18

How to Cite

(1)
Bugera, M. Y.; Herbeda, A. V.; Tarasenko, K. V.; Kondratov, I. S. The Preparative Synthetic Approach to α,α-Difluoro-γ-Aminobutyric Acid. J. Org. Pharm. Chem. 2020, 18, 55-59.

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Section

Original Researches