General procedure for the synthesis of 2-bromo-1-(6-bromonaphthalen-2-yl)ethanone from 2-acetyl-6-bromonaphthalene: Bromine (3.32 g, 1.07 mL, 20.8 mmol) was slowly added dropwise to a heated solution of 1-(6-bromonaphthalen-2-yl)ethanone (5.18 g, 20.8 mmol) dissolved in acetic acid (100 mL). After completion of the reaction, the mixture was cooled to room temperature. The precipitate was collected by filtration, washed with ether (Et2O) and dried under vacuum to afford 2-bromo-1-(6-bromonaphthalen-2-yl)ethanone (5.02 g, 73% yield).
[1] Patent: WO2011/91446, 2011, A1. Location in patent: Page/Page column 7; 11
[2] Patent: US2012/230951, 2012, A1. Location in patent: Page/Page column 85
[3] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2011, vol. 50, # 4, p. 593 - 604
[4] Patent: CN107286150, 2017, A. Location in patent: Paragraph 0132; 0133; 0134; 0135
[5] Patent: WO2013/39878, 2013, A1. Location in patent: Page/Page column 109; 110