Reimer-Tiemann is not low-yielding (at least for p-methoxyphenol), only messy. Considering the necessary precursor (water, chloroform and NaOH), I think this is still a method worthy of some respect
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Also, how did you purify your end product? Did you obtain the pale oil after you removed toluene by distillation, or did you distill the benzaldehyde? On several occasions, I obtained a yellow oil after I removed toluene by distillation. When I wanted to purify the oil, there was a very pale yellow oil comming over before 2-hydroxy-5-methoxybenzaldehyde. I cannot remember at what temperature (but more than toluene) and - as usual - can't find my notes
. The very pale yellow oil has an odour very different from toluene though. The benzaldehyde mixture turns into black. Further increasing the temperature will furnish me the benzaldehyde as a pale yellow oil, pleasantly odouring and staining my hands yellow.