Dimethyl Sulfoxide → Methyl 1H-pyrrole-1-carboxylate

Beteiligte Stoffe

Reaktionsschritte

Potassium (5.85 g, 0.15 mol) was added to a solution of 10 ml pyrrole (0.145 mol) in 80 ml hot cyclohexane in several portions. The mixture was refluxed for 1 hour. To this cold solution was added 15 g (0.16 mol) methyl chloroformate slowly. After addition, the mixture was stirred at room temperature for 30 minutes. During this period, 2.5 ml dimethyl sulfoxide was added for catalysis. After quenching with ice-water, the organic layer was separated and the aqueous layer extracted with ether. The combined organic layer was washed with 10% sodium bicarbonate, sat. sodium chloride and dried over magnesium sulfate. Removal of solvent yielded 17.4 g of a liquid. Bulb to bulb distillation gives 16.5 g N-carbomethoxy pyrrole 21 as a colorless liquid, yield 91%. The product requires storage at −20° C.

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