Use of Silyl Ester and Enamine Protection for an Efficient Alternate Synthesis of (1S,2S,5R,6S)-2-[(2′S)-(2′-Amino)propionyl]aminobicyclo[3.1.0]hexane-2,6-dicarboxylic Acid Hydrochloride (LY544344·HCl)

Abstract

An alternate synthesis of title compound (5) using N-(2-methoxycarbonyl-1-methylvinyl)-l-alanine sodium salt (6) and 2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (1) was successfully completed. Incorporation of silyl ester protection and the use of an enamine-protecting group allowed for the elimination of several processing steps.

Keywords

acylations - protecting groups - amino acids - drugs - process development

References

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5

KF analysis was used to determine quantity of water to add to obtain a 10% by weight solution of water prior to addition to anti-solvent.