Abstract:The preparation process of Sacubitril was industrially improved. The commercial product N-[(1R)-2-[1,1'-biphenyl]-4-yl-1-(hydroxymethyl)ethyl]carbamic acid 1,1-dimethylethyl ester (compound Ⅰ, CAS:1426129-50-1) was used as starting material. The intermediate V was obtained by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) oxidation, Wittig reaction, deethyl ester and recrystallization. The key intermediate Ⅵ was obtained by recrystallization with m(n-heptane)∶m (ethyl acetate) = 1∶1 after hydrogenation reduction of Pd/C. Finally, the target product Sacubitril (compound Ⅷ, CAS: 149709-62-6) was obtained by amidation after protection with ethyl ester. The key hydrogenation step was selected in detail in terms of reaction parameters such as solvents, additives, catalysts, temperature, pressure, time, and recrystallization solvents. A process route suitable for industrial production was determined, and three batches of kilogram scale in succession were carried out. The chiral structure of the key intermediate Ⅵ was analyzed by chiral HPLC, and the chiral purity was 99.98%. The total yield of the target product was about 50%, and the purity of the product was 100% by HPLC detection.