TMBA from 5-hydroxyvanillin with TMP

[Mephisto]

Is it possible to use TMP (trimethyl phosphate) for a two step methylation (to substitute two hydroxyl-groups with two methoxy-groups)? I thought about a methylation of 5-hydroxyvannilin to 3,4,5-trimethoxybenzaldehyde (TMBA). US Pat 4,453,004 describes a way to methylate syringaldehyde to TMBA, but I couldn't find anything about the direct way 5-OH-vanillin --> TMBA.

I think, it would be a good choice to run it analogue to US Pat 3,855,306 (3,4,5-trimethoxybenzaldehyde from 5-hydroxyvanillin), just with TMP instead of the DMS (acetone as solvent). What do you think?

[Bandil]

In my experience, DMS is fully substitutable with TMP in all cases (note, I only speak for the subtrates I have worked with, there might be some freak molecules where it wont work. The yields are generally 10-20% lower than the corresponding DMS runs. But considering the lesser toxicity and availability, i'd say its worthwile to live with  

[hest]

I’m sure Bandil is right (but I prefer DMS, that is because I'm so brave)