4-Methylbenzoyl Chloride → Ethyl 1,2-dimethyl-5-(p-toluoyl)pyrrole-3-carboxylate

HRID 2071688Notes

Reaction equation

HRID 2071688 reaction equation
[C:1]1([CH3:10])[CH:6]=[CH:5][C:4]([C:7](Cl)=[O:8])=[CH:3][CH:2]=1.[Cl-].[Al+3].[Cl-].[Cl-].[CH3:15][N:16]1[CH:20]=[CH:19][C:18]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[C:17]1[CH3:26]>ClC(Cl)C>[CH3:15][N:16]1[C:20]([C:7]([C:4]2[CH:5]=[CH:6][C:1]([CH3:10])=[CH:2][CH:3]=2)=[O:8])=[CH:19][C:18]([C:21]([O:23][CH2:24][CH3:25])=[O:22])=[C:17]1[CH3:26]

Participants

5

Reactant 3

HCID 134054-Methylbenzoyl ChlorideHCID 6451240Aluminum(III) ChlorideHCID 12211514Ethyl 1,2-dimethyl-1H-pyrrole-3-carboxylate

Product 1

HCID 21411872Ethyl 1,2-dimethyl-5-(p-toluoyl)pyrrole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent2×

Procedure

Thirty-seven grams of p-toluoyl chloride (0.243 mole) is added to a suspension of 32.4 g. (0.243 mole) of aluminum chloride in 80 ml of dichloroethane. The resulting solution is then added dropwise to a solution of 40.7 g. (0.243 mole) of ethyl 1,2-dimethylpyrrole-3-carboxylate in 80 ml of dichloroethane cooled in an ice bath. After the addition is complete, the resulting solution is stirred at room temperature for 20 minutes, is refluxed for 20 minutes, and is then poured into an ice-3N hydrochlorice acid mixture. The organic phase is separated and is washed twice with concentrated sodium chloride solution, after which it is dried over magnesium sulfate. Evaporation of the solvent yields a residue from which the desired product crystallized. Further product is obtained by chromatography of the mother liquor over acid-washed alumina in hexane using benzene as the eluant. Evaporation of the first compound-bearing fractions yields the desired product. Recrystallization of the combined yields of product from 95% ethanol and then methanol gives as pure product ethyl 1,2-dimethyl-5-(p-toluoyl)pyrrole-3 -carboxylate; m.p. 98°-100° C.

Workup

  1. additionThe resulting solution is then added dropwise to a solution of 40.7 g
  2. additionAfter the addition
  3. temperatureis refluxed for 20 minutes
  4. customThe organic phase is separated
  5. washis washed twice with concentrated sodium chloride solution
  6. dry with materialafter which it is dried over magnesium sulfate
  7. customEvaporation of the solvent

Sources & evidence

ORD record
ord-595ddc11310740428e838380b4f6ddf3
Source dataset
uspto-grants-1977_09
Patent number
US04048191

Reaction notes

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