Chlorosulfonic acid → Methyl 1-methyl-5-(4-methylbenzoyl)-1H-pyrrole-2-acetate

HRID 370928Notes

Reaction equation

HRID 370928 reaction equation
CN=[C:3](Cl)[C:4]1[CH:9]=[CH:8][C:7]([CH3:10])=[CH:6][CH:5]=1.ClS(O)(=O)=O.[CH3:17][N:18]1[CH:22]=[CH:21][CH:20]=[C:19]1[CH2:23][C:24]([O:26][CH3:27])=[O:25].C([O-])(=[O:30])C.[Na+]>O>[CH3:17][N:18]1[C:22]([C:3](=[O:30])[C:4]2[CH:5]=[CH:6][C:7]([CH3:10])=[CH:8][CH:9]=2)=[CH:21][CH:20]=[C:19]1[CH2:23][C:24]([O:26][CH3:27])=[O:25]

Participants

6

Reactant 4

HCID 24638Chlorosulfonic acidHCID 103992Methyl 1-methylpyrrol-2-acetateHCID 517045Sodium AcetateHCID 12410496N-Methyl 4-Methylbenzimidoyl Chloride

Product 1

HCID 118468Methyl 1-methyl-5-(4-methylbenzoyl)-1H-pyrrole-2-acetateYield 37%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

N-Methyl 4-methylbenzimidoyl chloride (3.85 g, 23 mmole) was treated with alcohol free chloroform (4.5 ml) and chlorosulfonic acid (0.2 g, 1.7 mmole). Methyl 1-methyl-1H-pyrrole-2-acetate (3.5 g, 23 mmole) was added in one portion, the reaction was fitted with a calcium chloride drying tube and stirred overnight. The reaction was quenched with saturated aqueous sodium bicarbonate. The phases were separated and the organic phase was concentrated under reduced pressure. The residue (6.6 g of a red oil) was dissolved in methanol (50 ml) and treated with sodium acetate (3 g, 36 mmole) and water (10 ml). The reaction was heated at reflux overnight, then cooled in an ice bath. The title compound crystallized and was isolated by filtration, washed with cold methanol, and air dried to yield 2.3 g (37%) of a light tan solid, m.p. 117°-119° C.

Workup

  1. customthe reaction was fitted with a calcium chloride drying tube
  2. customThe reaction was quenched with saturated aqueous sodium bicarbonate
  3. customThe phases were separated
  4. concentrationthe organic phase was concentrated under reduced pressure
  5. dissolutionThe residue (6.6 g of a red oil) was dissolved in methanol (50 ml)
  6. temperatureThe reaction was heated
  7. temperatureat reflux overnight
  8. temperaturecooled in an ice bath
  9. customThe title compound crystallized
  10. customwas isolated by filtration
  11. washwashed with cold methanol, and air
  12. customdried

Sources & evidence

ORD record
ord-7f234a72010a4c11a9624a66ef33bb94
Source dataset
uspto-grants-1985_07
Patent number
US04528382

Reaction notes

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