Ethyl 1,4-dimethyl-1H-pyrrole-2-acetate → ethyl 5-(4-chlorobenzoyl)-1,4-dimethyl-1H-pyrrole-2-acetate
Reaction equation
[Cl:1][C:2]1[CH:11]=[CH:10][C:5]([C:6](C#N)=[O:7])=[CH:4][CH:3]=1.[CH3:12][N:13]1[CH:17]=[C:16]([CH3:18])[CH:15]=[C:14]1[CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21]>>[Cl:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([C:17]2[N:13]([CH3:12])[C:14]([CH2:19][C:20]([O:22][CH2:23][CH3:24])=[O:21])=[CH:15][C:16]=2[CH3:18])=[O:7])=[CH:4][CH:3]=1Participants
Procedure
A 1.50 g (0.0090 mole) sample of 4-chlorobenzoylcyanide was added over a one-hour period to 1.50 g (0.0082 mole) of ethyl 1,4-dimethylpyrrole-2-acetate at 120°-130° through which nitrogen was slowly bubbled. The mixture was heated for 27 hours. The resulting oil was chromatographed on silica gel with successive elution with hexane and 1,1,1-trichloroethane. The solvent was evaporated in vacuo from compound-bearing fractions. The residue was chromatographed through a Waters Associates, Prep LC, System 500 with elution with a 2:3 mixture of hexane:1,1,1-trichloroethane. Evaporation of solvent from the second compound-bearing fraction afforded solid which was recrystallized from methanol to give 0.74 g (28 percent yield) of ethyl 5-(4-chlorobenzoyl)-1,4-dimethylpyrrole-2-acetate, mp 108°-109°, undepressed by admixture with authentic material.
Workup
- customwas slowly bubbled
- temperatureThe mixture was heated for 27 hours
- customThe resulting oil was chromatographed on silica gel with successive elution with hexane and 1,1,1-trichloroethane
- customThe solvent was evaporated in vacuo from compound-bearing fractions
- customThe residue was chromatographed through a Waters Associates, Prep LC, System 500 with elution with a 2:3 mixture of hexane
- customEvaporation of solvent from the second compound-bearing fraction
- customafforded solid which
- customwas recrystallized from methanol
Sources & evidence
- ORD record
- ord-39f52380f404403c8c5b9004f5772ed9
- Source dataset
- uspto-grants-1981_03
- Patent number
- US04255335
Reaction notes
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