Citric Acid → (2R,4S)-2-methyl-4-((2-methylpropan-2-yl)oxycarbonylamino)-5-(4-phenylphenyl)pentanoic acid

HRID 1500446Notes

Reaction equation

HRID 1500446 reaction equation
Cl.[CH2:2]([O:4][C:5](=[O:24])[C@@H:6]([CH3:23])[CH2:7][C@H:8]([NH2:22])[CH2:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[CH:12][CH:11]=1)[CH3:3].[C:25]1([C:47]2[CH:52]=[CH:51][CH:50]=[CH:49][CH:48]=2)[CH:30]=[CH:29][C:28]([CH2:31][C@@H:32]([NH:39][C:40]([O:42][C:43]([CH3:46])([CH3:45])[CH3:44])=[O:41])[CH2:33][C@@H:34]([CH3:38])[C:35]([OH:37])=[O:36])=[CH:27][CH:26]=1.[C:53](Cl)(=[O:58])[C:54]([CH3:57])([CH3:56])[CH3:55].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C(OC(C)C)(=O)C.O.C(N(CC)CC)C>[CH2:2]([O:4][C:5](=[O:24])[C@H:6]([CH3:23])[CH2:7][C@H:8]([NH:22][C:53](=[O:58])[C:54]([CH3:57])([CH3:56])[CH3:55])[CH2:9][C:10]1[CH:11]=[CH:12][C:13]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[CH:14][CH:15]=1)[CH3:3].[C:25]1([C:47]2[CH:48]=[CH:49][CH:50]=[CH:51][CH:52]=2)[CH:26]=[CH:27][C:28]([CH2:31][C@@H:32]([NH:39][C:40]([O:42][C:43]([CH3:46])([CH3:44])[CH3:45])=[O:41])[CH2:33][C@@H:34]([CH3:38])[C:35]([OH:37])=[O:36])=[CH:29][CH:30]=1

Participants

9

Reactant 4

HCID 311Citric AcidHCID 62493Pivaloyl chlorideHCID 46193546(2R,4S)-2-methyl-4-((2-methylpropan-2-yl)oxycarbonylamino)-5-(4-phenylphenyl)pentanoic acidHCID 66739279HCID 66739279, compound

Product 2

HCID 46193546(2R,4S)-2-methyl-4-((2-methylpropan-2-yl)oxycarbonylamino)-5-(4-phenylphenyl)pentanoic acidHCID 66739227HCID 66739227, compound

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 7915Isopropyl AcetateSolvent3×HCID 8471TriethylamineSolvent

Procedure

10 g (2S,4S)-4-amino-5-biphenyl-4-yl-2-methylpentanoic acid ethyl ester hydrochloride (3-a, R1=R2=H, R3=Et) in isopropyl acetate (50 ml) is added to a mixture of pivaloyl chloride (4.1 ml) in isopropyl acetate (50 ml). The mixture is then stirred for 40 min at room temperature. Triethylamine (10.3 ml) in isopropyl acetate (30 ml) is then added over a period of 1 h. The resulting mixture is stirred for 16 h. Citric acid (7.5 g) dissolved in water (30 ml) is added and the phases are separated. The organic phase is washed twice with water (30 ml) and concentrated in vacuo to give (2R,4S)-5-Biphenyl-4-yl-4-(2,2-dimethylpropionylamino)-2-methylpentanoic acid ethyl ester (3-a, R1=Piv, R2=H, R3=Et). 1H NMR (DMSO): 1.05 (9H), 1.09 (3H), 1.15 (3H), 1.54 (1H), 1.78 (1H), 2.48 (1H), 2.72 (2H), 3.97 (1H), 4.00 (2H), 7.15 (1H), 7.25 (2H), 7.34 (1H), 7.45 (2H), 7.55 (2H), 7.62 (2H).

Workup

  1. stirringThe resulting mixture is stirred for 16 h
  2. additionis added
  3. customthe phases are separated
  4. washThe organic phase is washed twice with water (30 ml)
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-c8f5210038fd41af99f9e6e577c67a4e
Source dataset
uspto-grants-2015_12
Patent number
US09206116B2

Reaction notes

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