Sacubitril

Sacubitril, AHU 377

4-[[(2S,4R)-5-ethoxy-4-methyl-5-oxo-1-(4-phenylphenyl)pentan-2-yl]amino]-4-oxobutanoic acid

5-(Biphenyl-4-yl)-4(S)-(3-carboxypropionamido)-2(R)-methylbutyric acid ethyl ester

AHU377; AHU-377; Sacubitril; 149709-62-6; UNII-17ERJ0MKGI; Alpha-ethyl (alphaR,gammaS)-gamma-<(3-carboxy-1-oxopropyl)amino>-alpha-methyl<1,1′-biphenyl>-4-pentanoate

Sacubitril is an antihypertensive drug used in combination with valsartan. The combination drug, valsartan/sacubitril, known during trials as LCZ696 and marketed under the brand name, Entresto, is a treatment for heart failure.^[1] It was approved under the FDA’spriority review process for use in heart failure on July 7, 2015.

Mechanism of action

Sacubitril is a prodrug that is activated to LBQ657 by de-ethylation via esterases.^[2] LBQ657 inhibits the enzyme neprilysin,^[3] which is responsible for the degradation of atrial and brain natriuretic peptide, two blood pressure lowering peptides that work mainly by reducing blood volume.^[4]

SYNTHESIS

WO-2008031567

http://www.google.com/patents/WO2008031567A1?cl=en

the following steps:

and optionally the following additional steps:

 ………..

PATENT

http://www.google.com/patents/EP0555175A1

Example 1
• To a solution of N-(3-carbo(t)butoxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-2R-methylbutanoic acid ethyl ester (0.80 g) in 15 ml of CH₂CI₂ at room temperature are added 3 ml of trifluoroacetic acid. The mixture is stirred overnight and concentrated. The residue is dissolved in tetrahydrofuran (THF), and 6.5 ml of 1 N NaOH is added. The mixture is concentrated and triturated with ether. The solid can be recrystallized from methylene chloride-hexane to give sodium N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-2R-methyl butanoic acid ethyl ester melting at 159-160°C; [a]D20 = – 11.4° (methanol).

The starting material is prepared as follows:

• A solution of a-t-BOC-(R)-tyrosine methyl ester (5.9 g, 20 mmol) and pyridine (8 mL, 100 mmol) in methylene chloride (30 mL) is cooled to 0-5°C. Trifluoromethanesulfonic anhydride (4 mL, 23 mmol) is added at 0-5°C, and the resulting mixture is held for another 30 minutes. The reaction mixture is diluted with water (60 mL) and methylene chloride (100 mL), and washed sequentially with 0.5 N sodium hydroxide solution (1 x 50 mL), water (1 x 60 mL), 10% citric acid solution (2 x 75 mL) and water (1 x 60 mL). The organic phase is dried over MgS0₄ and concentrated to an oil. The oil is purified by column chromatography (silica gel, hexane/ethyl acetate, 2:1 to give methyl(R)-2-(t-butoxycarbonylamino)-3-[4-(trifluoromethylsulfonyloxy)phenyl]-propionate which crystallizes on standing; m.p. 46-48°C; [a]²⁰ _D-36.01⁰ (c=1, CHCI₃).
• Nitrogen is passed through a suspension of (R)-2-(t-butoxycarbonylamino)-3-[4-(trifluoromethylsulfonyloxy)-phenyl]-propionate (1.75mmol), phenylboronic acid (3.5 mmol), anhydrous potassium carbonate (2.63 mmol) and toluene (17 mL) for 15 minutes. Tetrakis(triphenyiphosphine)paiiadium(0) is added, and the mixture is heated at 85-90° for 3 hours. The reaction mixture is cooled to 25°C, diluted with ethyl acetate (17 mL) and washed sequentially with saturated sodium bicarbonate (1 x 20 mL), water (1 x 20 mL), 10% citric acid (1 x 20 mL), water (1 x 20 mL) and saturated sodium chloride solution (1 x 20 mL). The organic phase is concentrated, and the residue is purified by column chromatography (silica gel, hexane/ethyl acetate 2:1) to yield methyl (R)-2-(t-butoxycarbonylamino)-3-(p-phenylphenyl)-propionate which can also be called N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine methyl ester.
• To a solution of N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine methyl ester (6.8 g) in 60 ml of THF and 20 ml of methanol are added 20 ml of aqueous 1 N sodium hydroxide solution. The mixture is stirred for 1 h at room temperature and then acidified with 21 ml of 1 N hydrochloric acid. The aqueous solution is extracted 3x with ethyl acetate. The combined organic extracts are dried (MgS0₄), filtered and concentrated to give N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine, m.p. 98-99°C; [a]²°_D -18.59° (c=1, methanol).
• To a solution of N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine (4.8 g) in 70 ml of methylene chloride (CH₂CI₂) at 0°C with 1.65 g of N,O-dimethylhydroxylamine HCI, 1.7 g of triethylamine and 2.85 g of hydroxybenzotriazole are added 5.37 g of 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride. The mixture is stirred 17 h at room temperature. The mixture is concentrated taken up in ethyl acetate (EtOAc) and washed with saturated sodium bicarbonate, 1N HCI and brine, then dried (MgS0₄), filtered and concentrated to give N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine N,O-dimethyl hydroxylamine amide.
• To a 0°C solution of N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine N,O-dimethyl hydroxylamine amide (5.2 g) in 250 ml of diethyl ether are added 0.64 g of lithium aluminum hydride. The reaction is stirred for 30 min. and quenched with aqueous potassium hydrogen sulfate. The mixture is stirred for additional 5 min., poured onto 1N HCI, extracted (3x) with EtOAc, dried (MgS0₄), filtered, and concentrated to give N-(R)-4-t-butoxycarbonyl-(p-phenylphenyl)-alanine carboxaldehyde as a colorless oil.
• To a 0°C solution of N-(R)-t-butoxycarbonyl-(p-phenylphenyl)-alanine carboxaldehyde (4.4 g) in 200 ml of CH₂CI₂are added 10 g of carboethoxyethylidene phenyl phosphorane. The mixture is warmed to room temperature, stirred for 1 h, washed with brine, dried (MgS0₄), filtered and concentrated. The residue is chromatographed on silica gel eluting with (1:2) ether:hexane to give N-t-butoxycarbonyl-(4R)-(p-phenylphenylme- thyl)-4-amino-2-methyl-2-butenoic acid ethyl ester.
• A solution of N-t-butoxycarbonyl-(4R)-(p-phenylphenylmethyl)-4-amino-2-methyl-2-butenoic acid ethyl ester (4.2 g) in 400 ml of ethanol is suspended with 2.0 g of 5% palladium on charcoal and then is hydrogenated at 50 psi for 6h. The catalyst is removed by filtration and the filtrate is concentrated to give N-t-butoxycarbonyl(4S)-(p-phenylphenylmethyl)-4-amino-2-methylbutanoic acid ethyl ester as a 80:20 mixture of diastereomers.
• To the N-t-butoxycarbonyl(4S)-(p-phenylphenylmethyl)-4-amino-2-methylbutanoic acid ethyl ester (4.2 g) in 40 ml of CH₂CI₂ at 0°C is bubbled dry hydrogen chloride gas for 15 min. The mixture is stirred 2 h and concentrated to give (4S)-(p-phenylphenylmethyl)-4-amino-2-methylbutanoic acid ethyl ester hydrochloride as a 80:20 mixture of diastereomers.
• To a room temperature solution of the above amine salt (3.12 g) in 15 ml of CH₂CI₂ and 15 ml of pyridine are added 13.5 g of succinic anhydride. The mixture is stirred for 17 h, concentrated, dissolved in ethyl acetate, washed with 1N HCI and brine, and dried (MgS0₄) to give N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenyl- methyl)-4-amino-2-methylbutanoic acid ethyl ester as a 80:20 mixture of diastereomers.
• The above N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-2-methylbutanoic acid ethyl ester diastereomeric mixture (3.9 g) and N,N-dimethylformamide-di-t-butyl acetal (8.8 ml) are heated at 80°C in 40 ml of toluene for 2 h. The mixture is poured onto ice- 1N HCI, extracted with ether, chromatographed on silica gel eluting with (2:1) toluene:ethyl acetate to give N-(3-carbo(t)butoxy-1-oxopropyl)-(4S)-(p-phenylphe- nylmethyl)-4-amino-2R-methylbutanoic acid ethyl ester as the more polar material and the corresponding (S,S) diastereomer as the less polar material.

Example 2

• To a solution of N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-(2R)-methylbutanoic acid ethyl ester (0.33 g) in 20 ml of (1:1) ethanol:tetrahydrofuran (THF) at room temperature are added 5 ml of 1 N sodium hydroxide solution (NaOH) and stirred for 17 h. The mixture is concentrated, dissolved in water and washed with ether. The aqueous layer is acidified with 1 N hydrochloric acid (HCI), extracted 3x with ethyl acetate (EtOAc), dried over magnesium sulfate (MgS0₄), filtered and concentrated. The residue is triturated with ether to yield N-(3-carboxy-1-oxopropyl)-(4S)-(p-phenylphenylmethyl)-4-amino-(2R)-methylbutanoic acid melting at 158-164°C, [α]_D ²⁰= -23.5° (methanol).

 1H NMR PREDICT

13C NMR PREDICT

COSY PREDICT

…………….

NMR…..http://www.chemietek.com/Files/Line3/CHEMIETEK,%20AHU-377%20,%20Lot%2001,%20NMR-MeOD,%201.1.pdf

Mol. Formula:C₂₄H₂₉NO₅ ∙ C₄H₁₁NO₃

MW:532.6

HPLC………http://www.chemietek.com/Files/Line2/CHEMIETEK,%20AHU-377%20,%20Lot%2001,%20HPLC.pdf

References

Patent	Submitted	Granted
ORGANIC COMPOUNDS [US2009156585]	2009-06-18
METHODS OF TREATMENT AND PHARMACEUTICAL COMPOSITION [US8101659]	2008-10-23	2012-01-24
Substituted Aminobutyric Derivatives as Neprilysin Inhibitors [US2010305145]	2010-12-02
PROCESS FOR PREPARING BIARYL SUBSTITUTED 4-AMINO-BUTYRIC ACID OR DERIVATIVES THEREOF AND THEIR USE IN THE PRODUCTION OF NEP INHIBITORS [US2009326066]	2009-12-31
Process for preparing 5-biphenyl-4-amino-2-methyl pentanoic acid [US8115016]	2010-05-06	2012-02-14
Methods of treatment and pharmaceutical composition [US7468390]	2003-07-31	2008-12-23
Process for Preparing 5-biphenyl-4-amino-2-methyl Pentanoic Acid [US2014249320]	2014-03-25	2014-09-04
Substituted Aminobutyric Derivatives as Neprilysin Inhibitors [US2012252830]	2012-06-07	2012-10-04
Process for preparing 5-biphenyl-4-amino-2-methyl pentanoic acid [US8716495]	2011-12-21	2014-05-06

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Sacubitril

Systematic (IUPAC) name
4-{[(2S,4R)-1-(4-Biphenylyl)-5-ethoxy-4-methyl-5-oxo-2-pentanyl]amino}-4-oxobutanoic acid
Clinical data
Legal status	Investigational
Identifiers
CAS Registry Number	149709-62-6
ATC code	None
PubChem	CID: 9811834
ChemSpider	7987587
Synonyms	AHU-377; AHU377
Chemical data
Formula	C24H29NO5
Molecular mass	411.49 g/mol