HCID 68825474, compound → HCID 178468675, compound

Participants

Reaction Steps

To the solution of 4-(2-ethoxycarbonyl-2-methanesulfonyl-vinylamino)-benzoic acid ethyl ester (example 61d) in phosphorous oxychloride (700 mL), Polyphosphoric acid (PPA, 445 g) was added. The resulted mixture was heated at 70 degrees for 8 hours under mechanical stirring. After the reaction, the reaction mixture was cooled to room temperature, and then phosphorous oxychloride was evaporated under reduced pressure. To the residue, water was added. The solid was filtered, collected, washed with water thoroughly, and then dried. Column chromatography gave 4-hydroxy-3-methanesulfonyl-quinoline-6-carboxylic acid ethyl ester (25 g, purity 70%). LC-MS m/e 232 (MH+)

Provenance & Evidence