Benzyl Bromide → (S)-benzyl 3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(tert-butoxycarbonylamino)propanoate

HRID 20865Notes

Reaction equation

HRID 20865 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:20][C:21]#[CH:22])[C:10]([O:12][CH2:13][C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].O=C1O[C@H]([C@H](CO)O)C([O-])=C1O.[Na+].[N-:36]=[N+:37]=[N-:38].[Na+].[CH:40]1[CH:45]=[CH:44][C:43]([CH2:46]Br)=[CH:42][CH:41]=1>CN(C=O)C.O.O.CCOC(C)=O>[CH2:46]([N:36]1[CH:22]=[C:21]([CH2:20][C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[C:10]([O:12][CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)=[O:11])[N:38]=[N:37]1)[C:43]1[CH:44]=[CH:45][CH:40]=[CH:41][CH:42]=1

Participants

8

Reactant 4

HCID 7498Benzyl BromideHCID 33557Sodium Azide2×HCID 23667548Sodium AscorbateHCID 57326824(S)-benzyl 2-(tert-butoxycarbonylamino)pent-4-ynoate

Product 1

HCID 59166425(S)-benzyl 3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(tert-butoxycarbonylamino)propanoate

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8857Ethyl AcetateSolventHCID 21962138N,N-Dimethylformamide--water (1/1)Solvent

Conditions

Temperature
65 °C

Procedure

To a mixture of (S)-benzyl 2-(tert-butoxycarbonylamino)pent-4-ynoate (0.50 g, 1.65 mmol), sodium ascorbate (0.036 g, 0.18 mmol), CuSO4-5H2O (0.022 g, 0.09 mmol) and NaN3 (0.13 g, 2.1 mmol) in DMF-H2O (5 mL, 4:1) at rt was added BnBr (0.24 mL, 2.02 mmol) and the mixture was warmed to 65° C. After 5 h LCMS indicated low conversion. A further portion of NaN3 (100 mg) was added and heating was continued for 12 h. The reaction was poured into EtOAc and H2O and shaken. The layers were separated and the aqueous layer extracted 3× with EtOAc and the combined organic phases washed (H2O×3, brine), dried (Na2SO4), filtered, and concentrated. The residue was purified by flash (Biotage, 40+M 0-5% MeOH in CH2Cl2; TLC 3% MeOH in CH2Cl2) to afford a light yellow oil which solidified on standing (748.3 mg, 104%). The NMR was consistent with the desired product but suggests the presence of DMF. The material was used as is without further purification. 1HNMR (400 MHz, DMSO-d6) δ 7.84 (s, 1H), 7.27-7.32 (m, 10H), 5.54 (s, 2H), 5.07 (s, 2H), 4.25 (m, 1H), 3.16 (dd, J=1.0, 5.3 Hz, 1H), 3.06 (dd, J=5.3, 14.7 Hz), 2.96 (dd, J=9.1, 14.7 Hz, 1H), 1.31 (s, 9H).

Workup

  1. temperatureheating
  2. waitwas continued for 12 h
  3. customThe layers were separated
  4. extractionthe aqueous layer extracted 3× with EtOAc
  5. washthe combined organic phases washed (H2O×3, brine)
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe residue was purified by flash (Biotage, 40+M 0-5% MeOH in CH2Cl2; TLC 3% MeOH in CH2Cl2)
  10. customto afford a light yellow oil which

Sources & evidence

ORD record
ord-cc1acbad8e974d6cb5b601239d4418b0
Source dataset
uspto-grants-2010_06
Patent number
US07745636B2

Reaction notes

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