Ammonium Chloride → 2,2-Bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid benzyl ester

HRID 2039000Notes

Reaction equation

HRID 2039000 reaction equation
[C:1](O[BH-](OC(=O)C)OC(=O)C)(=O)[CH3:2].[Na+].[CH2:15]([O:22][C:23](=[O:45])[C:24]([NH:37][C:38]([O:40][C:41]([CH3:44])([CH3:43])[CH3:42])=[O:39])([NH:29][C:30]([O:32][C:33]([CH3:36])([CH3:35])[CH3:34])=[O:31])[CH2:25]CC=O)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.Cl.[CH2:47]([O:49][C:50](=[O:54])[C@H:51]([CH3:53])[NH2:52])[CH3:48].[Cl-].[NH4+]>ClCCl>[CH2:15]([O:22][C:23](=[O:45])[C:24]([NH:29][C:30]([O:32][C:33]([CH3:36])([CH3:34])[CH3:35])=[O:31])([NH:37][C:38]([O:40][C:41]([CH3:42])([CH3:43])[CH3:44])=[O:39])[CH2:25][CH2:1][CH2:2][NH:52][CH:51]([C:50]([O:49][CH2:47][CH3:48])=[O:54])[CH3:53])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 2724356L-Alanine, ethyl ester, hydrochloride (1:1)HCID 5049666Sodium triacetoxyborohydrideHCID 866488762,2-Bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester

Product 1

HCID 866488772,2-Bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid benzyl esterYield 41.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Sodium triacetoxyborohydride (5 g, 23.5 mmol) was added to a solution of 2,2-bis(tert-butoxycarbonylamino)-5-oxo-pentanoic acid benzyl ester (3.34 g, 7.9 mmol) and alanine ethyl ester hydrochloride (3.62 g, 23.5 mmol) in dichloromethane (30 mL). After 1 hour saturated ammonium chloride (10 mL) was added and the mixture was stirred for 5 minutes. The aqueous phase was extracted with dichloromethane (2×15 mL), and the combined organic phases were dried over sodium sulfate, filtered and the solvent was removed under reduced pressure. The resulting residue was subjected to flash chromatography with eluent of (10% methanol in ethyl acetate) and hexane. The product-containing fractions were combined and the solvent was removed under reduced pressure to provide 2,2-bis(tert-butoxycarbonylamino)-5-(1-ethoxycarbonyl-ethylamino)-pentanoic acid benzyl ester (1.7 g, 3.3 mmol, 41%). C27H42N2O8 calculated 522.3 observed [M+1]+ 523.3; rt=2.08 min.

Workup

  1. extractionThe aqueous phase was extracted with dichloromethane (2×15 mL)
  2. dry with materialthe combined organic phases were dried over sodium sulfate
  3. filtrationfiltered
  4. customthe solvent was removed under reduced pressure
  5. customthe solvent was removed under reduced pressure

Sources & evidence

ORD record
ord-79e98d10799a480388e47dc2f8e58167
Source dataset
uspto-grants-2013_11
Patent number
US08575118B2

Reaction notes

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