Process for Preparing 5-biphenyl-4-amino-2-methyl Pentanoic Acid

摘要

The present invention relates to pyrrolidin-2-ones according to the formula (1), or salts thereof,;;wherein R1 is hydrogen or a nitrogen protecting group, methods for their preparation and their use in the preparation of NEP-inhibitors, particularly in the preparation of N-(3-carboxyl-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-(2R)-methyl butanoic acid ethyl ester or salt thereof.

主权项

1. A process for producing a compound according to formula (18) or a salt thereof comprising the steps a) providing a compound according to formula (1), or tautomer, or salt thereof, b) methylating the compound according to formula (1), or tautomer, or salt thereof, to obtain a compound according to formula (2), or tautomer, or salt thereof, c) reacting the compound according to formula (2), or tautomer, or salt thereof, with a ring opening agent to obtain a compound according to formula (3) or a salt thereof d) reacting a compound according to formula (3) or a salt thereof to obtain a compound according to formula (18) or a salt thereof, wherein in the above formulae R1 and R2 are independently, of each other, hydrogen or a nitrogen protecting group and R3 is hydrogen or alkyl.