How is 4-Fluoro-2-hydroxybenzaldehyde (CAS: 348-28-7) typically synthesized?

4-Fluoro-2-hydroxybenzaldehyde can be synthesized via the reduction of 4-fluoro-2-hydroxybenzaldehyde-2-oxide, or by the alkylation of 4-fluoro-2-hydroxybenzoic acid. Commonly, the synthesis involves the use of sodium borohydride as a reducing agent and is carried out in a polar aprotic solvent such as dimethyl sulfoxide (DMSO). The yield is generally around 85-90%, with high selectivity to the desired product.