4-HYDROXY-6-IODOQUINOLINE

Synthesis

The reaction was carried out by batchwise addition of 5-{[(4-iodophenyl)amino]methylene}-2,2-dimethyl-1,3-dioxane-4,6-dione (120 g) in diphenyl ether (1.3 L, 8.0 mol) at 240 °C for 1.5 hours. After completion of the reaction, the mixture was cooled to room temperature and poured into 1.5 L of hexane. The resulting suspension was filtered and the filter cake was broken and washed with hexane (2 x 500 mL). The solid was dried under vacuum to afford 6-iodo-4-hydroxyquinoline as a brown solid (80 g, 82% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ11.89 (d, J=4.0 Hz, 1H), 8.36 (d, J=2.3 Hz, 1H), 7.89-7.98 (m, 2H), 7.37 (d, J=8.6 Hz, 1H), 6.07 (dd, J=7.5,1.1 Hz, 1H); mass spectra (m /z) 272.0 (M+H+).

References

[1] Patent: US2012/41024, 2012, A1. Location in patent: Page/Page column 8; 10; 16
[2] Patent: EP2566477, 2015, B1. Location in patent: Paragraph 0157; 0159
[3] Journal of Medicinal Chemistry, 2016, vol. 59, # 10, p. 4867 - 4880