Hydrochloric Acid → 4-(2,4,6-Trifluorobenzoyl)-1H-pyrrole-2-carboxylic acid

HRID 1894706Notes

Reaction equation

HRID 1894706 reaction equation
[F:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[C:7]([F:12])[C:3]=1[C:4](Cl)=[O:5].[Al+3].[Cl-].[Cl-].[Cl-].[NH:17]1[CH:21]=[CH:20][CH:19]=[C:18]1[C:22]([OH:24])=[O:23].Cl>ClCCl>[F:1][C:2]1[CH:10]=[C:9]([F:11])[CH:8]=[C:7]([F:12])[C:3]=1[C:4]([C:20]1[CH:19]=[C:18]([C:22]([OH:24])=[O:23])[NH:17][CH:21]=1)=[O:5]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 12473Pyrrole-2-Carboxylic AcidHCID 1448952,4,6-Trifluorobenzoyl chlorideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 534025784-(2,4,6-Trifluorobenzoyl)-1H-pyrrole-2-carboxylic acidYield 97.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a 120 mL dichloromethane solution of 2,4,6-trifluorobenzoyl chloride (4.3 g, 0.022 mol) was added AlCl3 (8.8 g, 0.066 mol) under N2 at room temperature. After stirring for 15 min, 1H-pyrrole-2-carboxylic acid (2.4 g, 0.022 mol) was added in small portions over a 10 min period. Stirring continued at room temperature for 1 hr, then the reaction mixture was treated with dropwise addition of ice-water (20 mL) and 1N HCl to adjust pH to 1. After stirring for another 30 min, the reaction mixture was extracted with AcOEt (3×30 mL). The combined organic layers were washed with brine, dried over anhydrous Na2SO4, filtered and concentrated to give the title compound (5.8 g, 97% yield). 1H-NMR (500 MHz, CDCl3): δ 12.48 (br.s, 1H), 7.48 (s, 1H), 7.28-7.38 (m, 2H), 6.83 (s, 1H).

Workup

  1. stirringStirring
  2. waitcontinued at room temperature for 1 hr
  3. stirringAfter stirring for another 30 min
  4. extractionthe reaction mixture was extracted with AcOEt (3×30 mL)
  5. washThe combined organic layers were washed with brine
  6. dry with materialdried over anhydrous Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-966776c3292f4266af3a013fefda02c3
Source dataset
uspto-grants-2013_08
Patent number
US08513289B2

Reaction notes

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