348-27-6

2-Fluoro-4-hydroxybenzaldehyde is a useful reagent for preparation of 3,4-ring fused 7-azaindoles and deazapurines as potent JAK2 inhibitors.

Preparation of 2-fluoro-4-hydroxybenzaldehyde involves: (1) mixing 3-fluorophenol (I), potassium carbonate, and 2-bromopropane in an organic solvent, and heating to react to obtain 1-fluoro-3-isopropoxybenzene (II); (2) dissolving compound (II) in an organic solvent and reacting with a brominating reagent to obtain 1-bromo-2-fluoro-4-isopropoxybenzene (III); (3) dissolving compound (III) in tetrahydrofuran, dripping isopropylmagnesium chloride/tetrahydrofuran solution at -10°C to 0°C, adding dimethylformamide to react after Grignard exchange to obtain 2-fluoro-4-isopropoxybenzaldehyde (IV); and (4) reacting compound (IV) with boron trichloride and deprotecting.

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[5] Patent: WO2010/102154, 2010, A2. Location in patent: Page/Page column 55