反応 #167546

反応方程式

(S)-benzyl 2-(tert-butoxycarbonylamino)pent-4-ynoate

sodium ascorbate

NaN3

NaN3

BnBr

→

desired product

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

溶媒

DMF H2O

H2O

EtOAc

反応条件

後処理

1. 1
   温度heating
2. 2
   workup.WAITwas continued for 12 h
3. 3
   その他The layers were separated
4. 4
   抽出the aqueous layer extracted 3× with EtOAc
5. 5
   洗浄the combined organic phases washed (H2O x3, brine)
6. 6
   乾燥dried (Na2SO4)
7. 7
   ろ過filtered
8. 8
   濃縮concentrated
9. 9
   その他The residue was purified by flash (Biotage, 40+M 0-5% MeOH in CH2Cl2; TLC 3% MeOH in CH2Cl2)
10. 10
    その他to afford a light yellow oil which

実験手順

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 x3, 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).

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