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

HRID 1945336Notes

Reaction equation

HRID 1945336 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. 1H NMR (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). LCMS: Anal. Calcd. for C24H28N4O4: 436; found: 437 (M+H)+.

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-5917fcb8532c44638b441388ee0b9c8e
Source dataset
uspto-grants-2013_03
Patent number
US08394968B2

Reaction notes

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