Potassium Hydroxide → 3-Acetyl-4,5-dimethyl-1H-pyrrole-2-carboxylic acid

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Reaction Steps

A mixture of pyrrole ester 34 (8.2 g, 0.0392 mol), in ethanol and 100 mL of 10% potassium hydroxide were refluxed for 1 h. The mixture was cooled and concentrated in vacuo to an oil. Water was added to the oil, the mixture acidified with dilute HCl and extracted with ether. The organic phase was dried with anhy. sodium sulfate and concentrated in vacuo to a solid residue. The compound was recrystallized in 80 mL of ethanol to give 5.8 g of pure 3-acetyl-4,5-dimethyl-2-pyrrole carboxylic acid 35 as a solid. 1H NMR (DMSO-d6) δ 2.5 (s, 3H), 2.2 (s, 3H), 2.0 (s, 3H) ppm.

Provenance & Evidence