Препаративний метод синтезу α,α-дифлуоро-γ-аміномасляної кислоти

• Date: 2020
• Main Authors: Bugera, Maksym Ya., Herbeda, Andrii V., Tarasenko, Karen V., Kondratov, Ivan S.
• Format: Article
• Language: Ukrainian
• Published: National University of Pharmacy 2020
• Subjects: флуор; етилбромодифлуороацетат; γ-аміномасляна кислота; реакція приєднання; перегрупування Курціуса; 547.321 547.74
• Online Access: https://ophcj.nuph.edu.ua/article/view/ophcj.20.209030
• Journal Title: Journal of Organic and Pharmaceutical Chemistry

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