Benzyl Bromide → ethyl 3-(benzyloxy)-1-{2-[(tert-butoxycarbonyl)amino]ethyl}-1H-pyrazole-5-carboxylate

HRID 571722Notes

Reaction equation

HRID 571722 reaction equation
[CH2:1](Br)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:9]([O:13][C:14]([NH:16][CH2:17][CH2:18][N:19]1[C:23]([C:24]([O:26][CH2:27][CH3:28])=[O:25])=[CH:22][C:21]([OH:29])=[N:20]1)=[O:15])([CH3:12])([CH3:11])[CH3:10].C([O-])([O-])=O.[Cs+].[Cs+]>C(#N)C>[CH2:1]([O:29][C:21]1[CH:22]=[C:23]([C:24]([O:26][CH2:27][CH3:28])=[O:25])[N:19]([CH2:18][CH2:17][NH:16][C:14]([O:13][C:9]([CH3:10])([CH3:12])[CH3:11])=[O:15])[N:20]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 178469378HCID 178469378, compound

Product 1

HCID 86706489ethyl 3-(benzyloxy)-1-{2-[(tert-butoxycarbonyl)amino]ethyl}-1H-pyrazole-5-carboxylateYield 74.5%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

Benzyl bromide (0.13 mL, 1.1 mmol) was added to a stirred suspension of ethyl 1-{2-[(tert-butoxycarbonyl)amino]ethyl}-3-hydroxy-1H-pyrazole-5-carboxylate (0.3 g, 1 mmol) and Cs2CO3 (0.65 g, 2 mmol) in ACN (5 mL). The mixture was stirred at room temperature for 16 hours and the solvents were evaporated in vacuo. The crude product was diluted with water and extracted with AcOEt. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; AcOEt in heptane 0/100 to 50/50). The desired fractions were collected and the solvents evaporated in vacuo to yield ethyl 3-(benzyloxy)-1-{2-[(tert-butoxycarbonyl)amino]ethyl}-1H-pyrazole-5-carboxylate (0.29 g, 73% yield) as a colorless oil.

Workup

  1. customthe solvents were evaporated in vacuo
  2. additionThe crude product was diluted with water
  3. extractionextracted with AcOEt
  4. customThe organic layer was separated
  5. dry with materialdried (Na2SO4)
  6. filtrationfiltered
  7. customthe solvents evaporated in vacuo
  8. customThe crude product was purified by flash column chromatography (silica; AcOEt in heptane 0/100 to 50/50)
  9. customThe desired fractions were collected
  10. customthe solvents evaporated in vacuo

Sources & evidence

ORD record
ord-11d04d2f4ea84916a0c7557d74d78d38
Source dataset
uspto-grants-2015_05
Patent number
US09029366B2

Reaction notes

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