Ethyl isocyanate → Methyl 5-bromo-2-(3-ethylureido)isonicotinate

Participants

Reaction Conditions

Reaction Steps

Methyl 2-amino-5-bromoisonicotinate (200 g, 865 mmol) was dissolved in chloroform (1.2 L) and placed into a 2 L Parr apparatus. Ethyl isocyanate (204 mL, 2.59 mol) was added, and the Parr apparatus was heated at 40° C. for 36 h at which time the reaction was determined to be complete. The mixture was then cooled to room temperature, concentrated, and the solid was dissolved in 2:1 ethyl acetate: tetrahydrofuran (3 L). This solution was extracted with water (1 L), and the water was back extracted with ethyl acetate (300 mL). The organic layers were combined then dried over sodium sulfate, filtered, and concentrated yielding 261 g (quant) of methyl 5-bromo-2-(3-ethylureido)isonicotinate as a dark yellow solid.

Provenance & Evidence