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

HRID 1396502Notes

Reaction equation

HRID 1396502 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 colourless 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-eec387b120334a58bfcc8ebd7d074c62
Source dataset
uspto-grants-2014_12
Patent number
US08901125B2

Reaction notes

Loading…