Synthesis
Step 2: 5-bromo-8-methylquinoline (from Step 1) was dissolved in H2SO4-H2O (3:2) to prepare a 0.1 M solution. CrO3 (10 equiv.) was added to this solution and the reaction was carried out at 90 °C for 2 hours. After completion of the reaction, the mixture was poured into ice water and the precipitate was collected by filtration to afford 5-bromoquinoline-8-carboxylic acid in 62% yield as an orange solid. Mass spectrum (ES+) m/z 252,254 (M+H)+.
References
[1] Bioorganic and Medicinal Chemistry, 2010, vol. 18, # 8, p. 2836 - 2848
[2] Patent: WO2007/28789, 2007, A1. Location in patent: Page/Page column 34
[3] Patent: WO2013/96194, 2013, A1
[4] Patent: WO2015/84842, 2015, A1. Location in patent: Paragraph 0089
[5] Patent: WO2009/141386, 2009, A1. Location in patent: Page/Page column 162; 163
