Sodium borohydride → (2S)-2-(tert-butoxycarbonylamino)-5-(5,6,7,8-tetrahydroquinolin-8-ylamino)-pentanoic acid tert-butyl ester

HRID 899615

Reaction equation

HRID 899615 reaction equation
[C:1]([O:5][C:6](=[O:20])[C@@H:7]([NH:12][C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:8][CH2:9][CH2:10][NH2:11])([CH3:4])([CH3:3])[CH3:2].[N:21]1[C:30]2[C:29](=O)[CH2:28][CH2:27][CH2:26][C:25]=2[CH:24]=[CH:23][CH:22]=1.[BH4-].[Na+]>CO>[C:1]([O:5][C:6](=[O:20])[C@@H:7]([NH:12][C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:8][CH2:9][CH2:10][NH:11][CH:29]1[C:30]2[N:21]=[CH:22][CH:23]=[CH:24][C:25]=2[CH2:26][CH2:27][CH2:28]1)([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 4311764Sodium borohydrideHCID 7006667(S)-tert-Butyl 5-amino-2-((tert-butoxycarbonyl)amino)pentanoateHCID 117447776,7-Dihydro-5H-quinoline-8-one

Product 1

HCID 69157433(2S)-2-(tert-butoxycarbonylamino)-5-(5,6,7,8-tetrahydroquinolin-8-ylamino)-pentanoic acid tert-butyl esterYield 54%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of (2S)-5-amino-2-(tert-butoxycarbonylamino)-pentanoic acid tert-butyl ester (free base) (0.905 g, 3.11 mmol) in CH3OH (15 mL) was added 6,7-dihydro-5H-quinolin-8-one (0.504 g, 3.43 mmol) and the resultant solution was stirred at room temperature for 5 hours. Powdered NaBH4 (0.379 g, 9.98 mmol) was added, and the mixture was stirred at room temperature for 25 minutes then concentrated under reduced pressure. The residue was dissolved in CH2Cl2 (100 mL) and brine (20 mL). The phases were separated and the aqueous phase was extracted with CH2Cl2 (3×20 mL). The combined organic extracts were dried (Na2SO4) and concentrated. Purification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH) provided 0.700 g (54%) of (2S)-2-tert-butoxycarbonylamino-5-(5,6,7,8-tetrahydroquinolin-8-ylamino)-pentanoic acid tert-butyl ester as a yellow oil.

Workup

  1. concentrationthen concentrated under reduced pressure
  2. dissolutionThe residue was dissolved in CH2Cl2 (100 mL)
  3. customThe phases were separated
  4. extractionthe aqueous phase was extracted with CH2Cl2 (3×20 mL)
  5. dry with materialThe combined organic extracts were dried (Na2SO4)
  6. concentrationconcentrated
  7. customPurification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH)

Sources & evidence

ORD record
ord-249cbc6b535248f5888482ade88491cf
Source dataset
uspto-grants-2008_04
Patent number
US07354932B2

Linked notes

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