Study On The Biocatalytic Route To(2r,4s)-5-([1,1’-biphenyl]-4-yl)-4-((tert-butoxycarbonyl)amino)-2-methylpentanoic Acid

Heart failure occurs in the severe or critical stage of many heart diseases.In developed countries,patients account for 1.5%-2.0% of the total population.In China,the prevalence rate is as high as 10% in people over 70 years old.Traditional drugs,such as RAAS inhibitors,ARBs,MRAS and beta receptor antagonists,still have high all-cause mortality and hospitalization rate due to lower ejection fraction.Angiotensin receptor enkephalinase inhibitor(Arni)is a new type of drugs with a new mechanism of action in the treatment of heart failure.Among them,"lcz696" developed by Novartis company has shown good therapeutic effect in preclinical and clinical practice.However,the compound has the problems of low synthesis yield and patent protection.Therefore,this paper will focus on the analysis of its synthesis process and patent situation A new efficient and green synthetic process route was developed to avoid patent protection and provide high-quality API for the domestic market of the product.In this paper,after analyzing the original manufacturer’s synthetic route and the patent protection of related reaction conditions,a convenient and industrialized synthetic route is designed;1、Using biphenyl as raw material and introducing methyl chiral source into raw material,we designed a route from raw material 4-biphenylacetic acid to transaminase catalysis under the condition that the eighth precious metal catalyst protected by the original manufacturer can not be used to catalyze the conversion of carbonyl group to chiral amino group,and the original manufacturer used 10 steps of reaction from the raw material D-Tyrosine to the key intermediate sacc08 The total yield and purity of sacc04 were 58.3%and 99.75%,respectively.Then the key intermediate sacc08 was obtained by enzyme catalyzed reaction,which took 5 steps.2、We used sacc04 as substrate to screen 50 kinds of transaminases from the existing enzyme library,and finally determined that the chiral selectivity of ata-36 transaminase was the best,with EE value of 99.50%.Then,the conditions of p H value,reaction temperature,cosolvent,amino donor and substrate concentration in the process of enzyme reaction werescreened.The preliminary results showed that the p H value was about 10 and the reaction temperature was about 50℃,When the cosolvent system was 40% DMSO,the amino donor was 30% isopropylamine hydrochloride,and the substrate concentration was 10.0 g / L,the enzyme catalytic effect was the best,and the conversion rate could reach 83.55%.3、Considering the reuse of the enzyme and the difficulty of filtration in the post-treatment,we screened the conditions of enzyme immobilization,and finally determined the immobilization method with covalent bond.The optimal immobilization conditions were:amino epoxy resin hfa001,resin / crude enzyme powder = 4:1,phosphate buffer salt system(0.05 M,4 Vol,p H 8.0-8.5),and the immobilization time was 10 h.The purified water was washed twice,and the storage conditions were as follows: the wet product was stored at about8℃.The optimum reaction conditions were determined as follows: p H value is about 11,reaction temperature is 45-50℃,2 m isopropylamine hydrochloride is amino donor,cosolvent system is 40% DMSO,substrate concentration is 10.0 g / L,the enzyme catalytic reaction effect is the best,the conversion rate can reach about 85%.This study shows that the synthesis of sacc09,the key intermediate of lcz696,is feasible by transaminase catalysis,which greatly shortens the synthesis process and reduces the cost.It can provide a cheap new mechanism drug lcz696 for the later patients,reduce the burden of patients,improve the quality of life,and provide research ideas for the follow-up research.