Hydrochloric Acid → (2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acid

HRID 1469616Notes

Reaction equation

HRID 1469616 reaction equation
C([O:3][C:4](=[O:34])[C@H:5]([CH3:33])[CH2:6][C@H:7]([NH:21][C:22](=[O:32])[C:23]1[CH:28]=[C:27]([F:29])[C:26]([OH:30])=[C:25]([F:31])[CH:24]=1)[CH2:8][C:9]1[CH:14]=[CH:13][C:12]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[CH:11][CH:10]=1)C.[OH-].[Na+].Cl>CO>[C:12]1([C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)[CH:11]=[CH:10][C:9]([CH2:8][C@@H:7]([NH:21][C:22](=[O:32])[C:23]2[CH:28]=[C:27]([F:29])[C:26]([OH:30])=[C:25]([F:31])[CH:24]=2)[CH2:6][C@@H:5]([CH3:33])[C:4]([OH:34])=[O:3])=[CH:14][CH:13]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 67506121(2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acid ethyl ester

Product 1

HCID 59608305(2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acidYield 60.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Next, to a solution of (2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-methoxy-benzoylamino)-2-methyl-pentanoic acid ethyl ester (125 mg, 0.260 mmol) in DCM (2.6 mL) is slowly added BBr3 (2.60 mL, 2.60 mmol) under nitrogen. The reaction is stirred for 18 hours at rt. The reaction is quenched with MeOH, diluted with EtOAc, washed with H2O and brine, dried over MgSO4, and concentrated under reduced pressure. The obtained material is purified by preparative silica gel thin-layer chromatography (7% MeOH in DCM) to give 100 mg (2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acid ethyl ester. Next, to a solution of (2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acid ethyl ester (30 mg, 0.064 mmol) in MeOH (2 mL) at room temperature is added aqueous 1M NaOH (4 mL, 4.0 mmol). After stirring for 1 hour the reaction is quenched with aqueous 1M HCl (4 mL, 4.0 mmol). The mixture is concentrated under reduced pressure and filtered to remove NaCl salt. The obtained residue is purified by preparative silica gel thin-layer chromatography (7% MeOH in DCM) to give 17.1 mg of (2R,4S)-5-biphenyl-4-yl-4-(3,5-difluoro-4-hydroxy-benzoylamino)-2-methyl-pentanoic acid. HPLC Retention time 1.56 minutes (condition B); MS 440 (M+1); 1H NMR (400 MHz, ACETONITRILE-d3) δ ppm 1.19 (d, J=7.07 Hz, 3 H) 1.55 (ddd, J=14.27, 10.74, 3.79 Hz, 1 H) 1.90-1.96 (m, 1 H) 2.54-2.71 (m, 1 H) 2.91 (dd, J=6.69, 3.16 Hz, 2 H) 4.25-4.43 (m, 1 H) 6.49 (d, J=9.60 Hz, 2 H) 6.93 (d, J=8.84 Hz, 1 H) 7.33-7.42 (m, 3 H) 7.49 (t, J=7.71 Hz, 2 H) 7.61 (d, J=8.34 Hz, 2 H) 7.67 (dd, J=8.34, 1.26 Hz, 2 H).

Workup

  1. concentrationThe mixture is concentrated under reduced pressure
  2. filtrationfiltered
  3. customto remove NaCl salt
  4. customThe obtained residue is purified by preparative silica gel thin-layer chromatography (7% MeOH in DCM)

Sources & evidence

ORD record
ord-b044147869e74484a142751878f61ec7
Source dataset
uspto-grants-2015_04
Patent number
US09006249B2

Reaction notes

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