Mg(MeO)2 route to benzaldehydes

[lutesium]

After following the patent for formylation w/ Mg(MeO)2, my friend was left w a yellowish oil. All chemicals were reag. grade(except p-meophenol. But it was crystallyzed twice and were white, 5-7 cm needles. They can also be assumed as reag. grade.) and the scale was 3g p-meo phenol. is skilled at practical synthetic chemistry.

Everything went an its writtten in the patent to the last second, but after the evaporation of toluene he was left with a pale yellow oil whose identitiy was unknown to him as he was hoping for cs crystallyne solid. Is this 2-OH-4-MeO-Bzaldehyde or did he screw up the rxn.

[Vitus_Verdegast]

NO this is NOT 2-OH-4-MeO-Bzaldehyde!!!


_{...but 2-OH-5-MeO-benzaldehyde!}  


Yes, a yellow oil with a pleasant smell is what you should have. Interesting to see that you obtained what seems like a reasonably pure product from it, making the cumbersome steam-distillation process unnecessary.

How do you plan to alkylate it?

[lutesium]

That made me feel better to hear that thay lovely yellow oil is what I want
(I reccomend this Mg(MeO)2 route to anybody. Ist easy and high yielding. Thanx to other bees who posted the method and saved me from the messy low yield reimerr-tiemann.)

I plan alkylatin w/ MeI followed by reduction to the alcohol - halogenation of the benzylic -oh then reacting it w/cyanide and reduction w/ Na metal.

I know that Its a long long long process but I have no access to R-NO2 s to form a nitrostyrene which I REALLY would like to

btw does anybody know if p-methoxyphenol dissolves in benzene?

[GC_MS]

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   .

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.

[lutesium]

GC_MS : I obtained the oil after the evaporation of toluene. It is crystal clear and smells a bit like toluene.
I would steam distill it but didnt bother as it was a very small scale rxn. But the yield of the undistilled aldehyde is nearly quantitative.

Edit: And I didnt mean disrespect to the reimer-tiemann. It has always been the bridge of my dreams up to now