Synthesis
Preparation of the intermediate 1-bromo-4-(2-methoxy-2-methyldienyl)benzene (1AG-1): 2-(4-bromophenyl)acetic acid (75 g, 340 mmol) was suspended in ethanol (341 mL). Concentrated sulfuric acid (0.682 mL, 12.79 mmol) was added slowly and the reaction mixture was subsequently heated to reflux and maintained for 24 hours. Upon completion of the reaction, the mixture was concentrated to remove the solvent. The residue was diluted with ether and saturated sodium bicarbonate solution for acid-base neutralization. The organic and aqueous layers were carefully separated and the organic layer was subsequently washed with brine and dried over sodium sulfate. The dried organic phase was filtered and the filtrate was concentrated to give ethyl 2-(4-bromophenyl)acetate (80.2 g, 97% yield) as an off-white solid.
References
[1] Patent: WO2010/86820, 2010, A1. Location in patent: Page/Page column 53
[2] Journal of Medicinal Chemistry, 2008, vol. 51, # 21, p. 6665 - 6681
[3] Patent: US2013/79320, 2013, A1. Location in patent: Paragraph 0473; 0474
[4] Patent: WO2013/45451, 2013, A1. Location in patent: Paragraph 51
[5] European Journal of Medicinal Chemistry, 2014, vol. 86, p. 714 - 723
