Facile Synthesis of ortho-Halo-Substituted 4-Aryl-2-Aminobutyric Acids

Abstract

Herein we describe an efficient and practical route for the regioselective synthesis of 4-(5-bromo/chloropyrazol-1-yl)-2-aminobutyric acids. The compounds have been prepared by regioselective C-5 halogenation of 1-(3,3-dimethoxypropyl)-1H-pyrazole followed by a Strecker synthesis. In addition, Boc-protected 2-amino-4-(2-chlorophenyl)butyric acid and 2-amino-4-(3-chloropyridin-2-yl)butyric acid have been synthesized.

Key words

amino acids - 1-alkyl-5-halopyrazole - Strecker synthesis - Heck reaction - Grignard reaction

References

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