Hydrochloric Acid → Nalpha-Boc-Ndelta-Cbz-ornithinol

HRID 1067090Notes

Reaction equation

HRID 1067090 reaction equation
[C:1]([NH:8][C@H:9]([C:24](O)=[O:25])[CH2:10][CH2:11][CH2:12][NH:13][C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].C(N(C(C)C)CC)(C)C.ClC(OCC)=O.[BH4-].[Na+].Cl>O1CCCC1>[C:1]([NH:8][C@H:9]([CH2:24][OH:25])[CH2:10][CH2:11][CH2:12][NH:13][C:14]([O:16][CH2:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)=[O:15])([O:3][C:4]([CH3:6])([CH3:7])[CH3:5])=[O:2]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 4311764Sodium borohydrideHCID 7269338(2S)-5-{[(benzyloxy)carbonyl]amino}-2-{[(tert-butoxy)carbonyl]amino}pentanoic acid

Product 1

HCID 11772551Nalpha-Boc-Ndelta-Cbz-ornithinolYield 81.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A well, stirred cold solution (0° C.) of Nα-Boc-Nδ-Cbz-ornithine (5 g, 13.6 mmol), diisopropylethylamine (5.9 ml, 34 mmol), and tetrahydrofuran (60 ml) was treated with ethyl chloroformate (3.25 ml, 34 mmol) at 0° C. Sodium borohydride (2.58 g, 68 mmol) was added, followed by the slow addition of 1:1-tetrahydrofuran/water (10 ml) 30 minutes later. The reaction mixture was acidified with 6N hydrochloric acid and the solution was extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate and purified by chromatography to give Nα-Boc-Nδ-Cbz-ornithinol (3.9 g): 1H NMR (400 MHz, CDCl3) δ1.2-1.4 (m, 13H), 3.0 (t, J=6.4 Hz, 2H), 3.4 (s, 2H), 3.8 (s, 1H), 4.95 (s, 2H), and 7.1-7.2 (m, 5H).

Workup

  1. additionfollowed by the slow addition of 1
  2. extractionthe solution was extracted with dichloromethane
  3. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  4. custompurified by chromatography

Sources & evidence

ORD record
ord-286ee48808b749599e25e27c314e81ea
Source dataset
uspto-grants-2001_06
Patent number
US06245746B1

Reaction notes

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