2,5-Hexanedione → Ethyl (2,5-dimethyl-1H-pyrrol-1-yl)acetate

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Reaction Steps

Glycine ethyl ester HCl (22 g, 158 mmol) was added to a stirring mixture of hexane-2,5-dione (18 g, 158 mmol) in dichloromethane (100 mL) in an Erlenmeyer flask. To the stirring heterogeneous mixture was slowly added triethylamine (66 mL, 473 mmol). After 30 minutes, dichloromethane (50 mL) and NaHCO3 (sat. aq. 100 mL) were added and the mixture continued to stir for 20 minutes. The dichloromethane layer was injected directly onto a 330 g silica gel column and the product was eluted with 0-100% ethyl acetate in hexanes. Pertinent fractions were combined and concentrated to afford ethyl 2-(2,5-dimethyl-1H-pyrrol-1-yl)acetate as a white solid (16 g, 56%). 1H NMR (CDCl3/400 MHz) δ (ppm) 5.8 (s, 2H), 4.85 (s, 2H), 4.22 (q, 2H), 2.17 (s, 6H), 1.28 (t, 3H)

Provenance & Evidence