合成路线1

The reaction of L-phenylalanine (I) with benzyl chloride and K2CO3 gives the tribenzylated compound (II), which is condensed with acetonitrile by means of NaNH2 yielding 4(S)-(dibenzylamino)-3-oxo-4-phenylbutyronitrile (III). The reaction of (III) with benzylmagnesium chloride in THF affords the unsaturated, partially protected diaminohexenone (IV), which is reduced with NaBH4 and NaBH3(OTf) to provide a mixture of diastereomeric diaminohexanones, from which the desired diastereomer (V) is isolated by crystallization. The acylation of the free amino group of (V) with acylated anthranilic acid (VI) by means of HOBT gives the expected amide (VII), which is debenzylated by treatment with Pd/C and ammonium formate yielding intermediate (VIII). Finally this compound is acylated with the activated N-succinylcarbamate (IX) to afford the desired target compound.