Malonic Acid → 6-Bromo-4-hydroxy-7-methoxyquinolin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

POCl3 (5.07 ml, 54.4 mmol) was added to a mixture of 4-bromo-3-methoxyaniline (10 g, 49.5 mmol) and malonic acid (5.15 g, 49.5 mmol) with thorough mixing, and the solution was then heated to 105° C. After 5 min, the reaction began to bubble vigorously and eventually formed a hard foam, and heating was continued for 1 h. After cooling, water (200 mL) was added, and the mixture was stirred for 30 min. The solid was filtered off and washed with water. 2N NaOH (300 mL) was added to the solid, and stirring was continued overnight. The remaining solid was filtered off. EtOH (5 mL) was then added to the filtrate, and the basic layer was then acidified with concentrated HCl to pH 2. The resulting solid was then filtered off and washed with water. The solid was then transferred to a flask, and the remaining water was removed by stripping off EtOH (200 mL×2). The solid was then further dried under high vacuum for 15 h to yield 8.75 g (66%) of the title compound as an off-white solid. LRMS EST (M+H)+270.2/272.2.

Provenance & Evidence