[F:1][C:2]1[CH:10]=[CH:9][C:5]([C:6](Cl)=[O:7])=[CH:4][CH:3]=1.[Cl-].[Al+3].[Cl-].[Cl-].[CH3:15][N:16]1[CH:20]=[C:19]([CH3:21])[CH:18]=[C:17]1[CH2:22][C:23]([O:25][CH2:26][CH3:27])=[O:24]>ClCCCl>[CH3:15][N:16]1[C:20]([C:6](=[O:7])[C:5]2[CH:9]=[CH:10][C:2]([F:1])=[CH:3][CH:4]=2)=[C:19]([CH3:21])[CH:18]=[C:17]1[CH2:22][C:23]([O:25][CH2:26][CH3:27])=[O:24]A solution of 3.95 g. (0.025 mole) of p-fluorobenzoyl chloride and 3.32 g. (0.025 mole) of aluminum chloride in 20 ml. of 1,2-dichloroethane is added dropwise to a solution of 4.52 g. (0.025 mole) of ethyl 1,4-dimethylpyrrole-2-acetate in 20 ml. of 1,2-dichloroethane at room temperature. The reaction mixture is stirred for 2 hours, and then cooled and poured into ice-dilute HCl. The organic phase is separated and washed successively with N,N-dimethyl-1,3-propanediamine, dilute hydrochloric acid and a saturated solution of sodium chloride; dried over anhydrous magnesium sulfate; and the solvent evaporated. The residuc is triturated with hot hexane and crystals form upon cooling. There is obtained about 1.9 g. (25% yield) of ethyl 1,4-dimethyl-5-(p-fluorobenzoyl)-pyrrole-2-acetate as a white solid, m.p. 84-86° C. Upon recrystallization from methanol, the m.p. is 87-89° C.
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