8-Chloro-2-ethoxyquinolin-4-ol synthesis

Yield:861396-95-4 53%

Reaction Conditions:

in diphenylether at 240 - 250; for 0.133333 h;

Steps:

1G.C

Step C:; The condensation product 1g4 (1.73 g, 6.41 mmol) was dissolved in diphenylether (10 ml) and placed in a sand bath (300°C). The internal temperature wasmonitored and allowed to stay between 240-250°C for 8 minutes. The mixture wascooled and then directly loaded on a silica gel column and eluted first with hexanes,then with 30% EtOAc/Hexanes and finally 50% EtOAc/hexanes. The product wasconcentrated and dried in vacuo to give the corresponding 4-hydroxyquinolinederivative 1g5 as a beige crystalline solid (0.76 g, 53%). MS electrospray: (M + H)⁺;224 and (M - H)'; 222.

References:

WO2006/7700,2006,A1 Location in patent:Page/Page column 67