Tolmetin → Allyl 5-(4-methylbenzoyl)-1-methylpyrrole-2-acetate

Reaction equation

[Na].[CH3:2][C:3]1[CH:4]=[CH:5][C:6]([C:9]([C:11]2[N:15]([CH3:16])[C:14]([CH2:17][C:18]([OH:20])=[O:19])=[CH:13][CH:12]=2)=[O:10])=[CH:7][CH:8]=1.[CH2:21](Br)[CH:22]=[CH2:23]>CN(C=O)C>[CH3:2][C:3]1[CH:8]=[CH:7][C:6]([C:9]([C:11]2[N:15]([CH3:16])[C:14]([CH2:17][C:18]([O:20][CH2:23][CH:22]=[CH2:21])=[O:19])=[CH:13][CH:12]=2)=[O:10])=[CH:5][CH:4]=1

Participants

Procedure

The sodium salt of tolmetin (15.0 g, 47.6 mmol) and allyl bromide (4.3 ml, 49.9 mmol) were dissolved in DMF (50 ml) and the mixture was stirred at room temperature until the esterification was complete (~30 h). The solvent was removed in vacuo and the residue was partitioned between ether and water. The organic layer was separated, washed with water, 1 M sodium hydroxide, and brine, and dried over sodium sulfate. Evaporation gave allyl 5-(4-methylbenzoyl)-1-methylpyrrole-2-acetate (11.97 g, 85%) as a solid. ##STR26##