Cesium carbonate → ethyl 1-(5-chloro-2-nitrobenzyl)-4-methyl-1H-pyrrole-2-carboxylate

HRID 1877787Notes

Reaction equation

HRID 1877787 reaction equation
C(=O)([O-])[O-].[Cs+].[Cs+].[CH3:7][C:8]1[CH:9]=[C:10]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[NH:11][CH:12]=1.Br[CH2:19][C:20]1[CH:25]=[C:24]([Cl:26])[CH:23]=[CH:22][C:21]=1[N+:27]([O-:29])=[O:28]>CN(C=O)C>[Cl:26][C:24]1[CH:23]=[CH:22][C:21]([N+:27]([O-:29])=[O:28])=[C:20]([CH:25]=1)[CH2:19][N:11]1[CH:12]=[C:8]([CH3:7])[CH:9]=[C:10]1[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 643361Ethyl 4-methyl-1H-pyrrole-2-carboxylateHCID 124231272-(Bromomethyl)-4-chloro-1-nitrobenzene

Product 1

HCID 68156028ethyl 1-(5-chloro-2-nitrobenzyl)-4-methyl-1H-pyrrole-2-carboxylateYield 73.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

Under a nitrogen atmosphere with stirring add cesium carbonate (96 g, 295 mmoles) to a solution of ethyl 4-methyl-1H-pyrrole-2-carboxylate (30 g, 196 mmoles) in DMF (240 mL) and heat the reaction mixture to 40° C. to 45° C. for 1 hour. Cool the reaction mixture to room temperature and add a solution of 2-(bromomethyl)-4-chloro-1-nitro-benzene (54 g, 216 mmoles) in DMF (120 mL) drop-wise. Stir the resulting suspension for 1.5 h to 2.0 h, filter the solids and rinse the filtercake with DMF (45 mL). Transfer the solids to a clean reaction vessel, add water (200 mL) and cool the suspension to 10° C. to 15° C. with stirring for 1 h to 2 h. Filter the suspension, rinse with water (75 mL) and transfer the solids to another reaction vessel. Add ethanol (125 mL) and stir the suspension at 5° C. to 10° C. for 1 h to 2 h. Filter the solids, rinse the filtercake with ethanol (20 mL), and dry the solids in an oven at less than 50° C. under reduced pressure to give ethyl 1-(5-chloro-2-nitrobenzyl)-4-methyl-1H-pyrrole-2-carboxylate as a yellow solid (54 g, 94.1% purity, 73.3% yield).

Workup

  1. temperatureheat the reaction mixture to 40° C. to 45° C. for 1 hour
  2. stirringStir the resulting suspension for 1.5 h to 2.0 h
  3. filtrationfilter the solids
  4. washrinse the filtercake with DMF (45 mL)
  5. additionTransfer the solids to a clean reaction vessel, add water (200 mL)
  6. temperaturecool the suspension to 10° C. to 15° C.
  7. stirringwith stirring for 1 h to 2 h
  8. filtrationFilter the suspension
  9. washrinse with water (75 mL)
  10. stirringAdd ethanol (125 mL) and stir the suspension at 5° C. to 10° C. for 1 h to 2 h
  11. filtrationFilter the solids
  12. washrinse the filtercake with ethanol (20 mL)
  13. customdry the solids in an oven at less than 50° C. under reduced pressure

Sources & evidence

ORD record
ord-0ed75a72bb4c4c0abcc21842c1b8de1d
Source dataset
uspto-grants-2012_11
Patent number
US08314092B2

Reaction notes

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