Dimethylformamide → Ethyl 5-formyl-4-methyl-1h-pyrrole-3-carboxylate

Beteiligte Stoffe

Reaktionsschritte

POCl3 (4 mL, 1.1 eq) added to 9 mL (3 eq) of DMF cooled in an ice bath. After 15 mins, a solution of the 4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester (6 g, 39.2 mmol) in DMF (2M, 20 mL) was added to the reaction and stirring continued at rt. After 2 hr, the reaction mixture was diluted with water (100 mL) and basified to pH=11 with 1N NaOH. The aqueous layer was extracted into DCM (2×250 mL), washing the combined organic layers with water (2×400 mL), dried (MgSO4), filtered through a plug of silica and concentrated to afford a pinkish solid. Trituration with hexanes afforded 3.3 g (46%) of 5-formyl-4-methyl-1H-pyrrole-3-carboxylic acid ethyl ester as a tan solid

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