Benzocaine → 4-(6-Bromo-4-methyl-3-oxo-3,4-dihydro-pyrazin-2-ylamino)-benzoic acid ethyl ester

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Reaction Steps

A mixture of 3,5-dibromo-1-methyl-2(1H)pyrazinone (21.3 g; 79.5 mmol), ethyl 4-aminobenzoate (13.1 g; 79.5 mmol), and 1-methyl-2-pyrrolidinone (10 mL) was heated at 130 degrees for 1 hr. The mixture was cooled to room temperature, diluted with dichloromethane and filtered to give a dull brown solid. This was slurried with 0.5N NaOH, filtered, washed with water and diethyl ether to give 4-(6-bromo-4-methyl-3-oxo-3,4-dihydro-pyrazin-2-ylamino)-benzoic acid ethyl ester (1) as a light brown solid (21.3 g)

Provenance & Evidence