Tosylmethyl isocyanide → ethyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate

HRID 1590574Notes

Reaction equation

HRID 1590574 reaction equation
CC(C)([O-])C.[K+].[F:7][C:8]([F:17])([F:16])/[CH:9]=[CH:10]/[C:11]([O:13][CH2:14][CH3:15])=[O:12].C1(C)C=CC(S([CH2:27][N+:28]#[C-:29])(=O)=O)=CC=1>O1CCCC1>[CH2:14]([O:13][C:11]([C:10]1[C:9]([C:8]([F:16])([F:17])[F:7])=[CH:29][NH:28][CH:27]=1)=[O:12])[CH3:15]

Participants

5

Reactant 3

HCID 161915Tosylmethyl isocyanideHCID 5371261Ethyl (2E)-4,4,4-trifluoro-2-butenoateHCID 23665647Potassium tert-butoxide

Product 1

HCID 14370786ethyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-60 °C

Procedure

A solution of potassium t-butoxide (8.11 g, 0.075 mol) in tetrahydrofuran at -60° C. is treated dropwise with a mixture of ethyl 4,4,4-trifluorocrotonate (10.5 g, 0.063 mol) and p-tolylsulfonylmethylisocyanide (12.2 g, 0.063 mol) in tetrahydrofuran over a 1 hour period, stirred at -60° C. for 30 minutes, allowed to warm to room temperature and quenched with water. The reaction mixture is extracted with ether and ethyl acetate. The combined extracts are washed with brine, dried (MgSO4) and concentrated in vacuo to give a solid residue. Recrystallization from 1,2-dichloroethane affords the title compound as a tan solid, 7.3 g (56%), mp 163°-164° C.

Workup

  1. temperatureto warm to room temperature
  2. customquenched with water
  3. extractionThe reaction mixture is extracted with ether and ethyl acetate
  4. washThe combined extracts are washed with brine
  5. dry with materialdried (MgSO4)
  6. concentrationconcentrated in vacuo
  7. customto give a solid residue
  8. customRecrystallization from 1,2-dichloroethane

Sources & evidence

ORD record
ord-97b948fa1f984716bee03913dd84824f
Source dataset
uspto-grants-1993_04
Patent number
US05204332

Reaction notes

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