Synthesis
A synthesis of 4-bromo-2-methoxybenzaldehyde is reported from 1,4 dibromo 2-fluorobenzene. First, 2-fluoro-4-bromobenzaldehyde is prepared through metal halogen exchange and formylation with a formyl source at 0° C. After crystallization, this intermediate is reacted with methanol in the presence of potassium carbonate. Subsequently, 4-bromo-2-methoxy-benzaldehyde is crystallized.
References
[1] Patent: WO2017/182495, 2017, A1. Location in patent: Page/Page column 141-142
[2] Patent: WO2005/63756, 2005, A1. Location in patent: Page/Page column 33-34
[3] Organic Letters, 2017, vol. 19, # 19, p. 5122 - 5125
[4] Patent: WO2009/158426, 2009, A1. Location in patent: Page/Page column 64-65