Sacubitril intermediate and preparation method thereof

A method of preparing sacubitril,

• comprising the following steps:
• a) preparing a compound of Formula (VI) by an enzymic catalytic reaction of a compound of Formula (V) in the presence of ω-transaminase and phosphopyridoxal,
• b) optionally, preparing a compound of Formula (VII) from the compound of Formula (VI):
• c) preparing sacubitril from the compound of Formula (VII),
• wherein:
• R1 is phenyl, methoxy, hydroxy, chloro, bromo, iodo, mesylate, triflate or 4-methylbenzenesulfonate;
• R2 is
• R3 is H, —(C1-C4)alkyl or —(C1-C4)alkyl-aryl;
• and
• R4 is H, —(C1-C4)alkyl, —(C3-C6)heterocyclyl, —(C1-C4)alkyl-aryl, trimethylsilyl, triethylsilyl or t-butyldimethylsilyl.