Propylene Oxide → Imidazo1,2-aquinoline-2-carboxylic acid, 8-bromo-5-chloro-, ethyl ester

Participants

Reaction Steps

1 g of 2-amino-7-bromo-4-chloroquinoline was suspended in 10 ml of dimethoxyethane and then a solution of 1 g of ethyl bromopyruvate and 300 mg of propylene oxide in 10 ml of dimethoxyethane was added. The mixture was stirred at room temperature for 2 days and 300 mg of ethyl bromopyruvate were then added. Stirring was continued for a further day and the precipitated quaternary salt was filtered off, washed with ether and then was suspended in 20 ml of ethanol. The mixture was heated at reflux for 2 hours and the solvent was removed under vacuum. The residue was partitioned between CHCl3 /Na2CO3 solution and the organic solution was dried over MgSO4 and the solvent was removed to leave a cream solid. This was purified by chromatography over silica with 5% methanol in chloroform as eluent and the product was crystallized from chloroform/ether to obtain pale cream needles of ethyl 8-bromo-5-chloroimidazo-[1,2-a]-quinoline-2-carboxylate melting at 206° to 207° C.

Provenance & Evidence