Scheme 2. Synthesis of the NEP inhibitor AR58. a) Bis (trimethylsilyl)-acetamide, 708C; b) BOP, DIEA, NMP, solid-phase peptide synthesis then cleavage from the MBHA resin and final deprotection of the side chains of the amino acid residues (tert-butyl ether: Tyr, tert-butyl ester: Asp, N-tert-butoxycarbonyl: Lys) by trifluoroacetic acid to form R1 and the desired product. BOP= 1-benzotriazolyloxytris (dimethylamino)-phosphonium ...