The Vespiary

The Hive => Chemistry Discourse => Topic started by: Mephisto on June 09, 2004, 12:41:00 PM

Title: TMBA from 5-hydroxyvanillin with TMP
Post by: Mephisto on June 09, 2004, 12:41:00 PM

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?

Title: In general yes
Post by: Bandil on June 09, 2004, 02:45:00 PM

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  :)

Title: Fine
Post by: hest on June 09, 2004, 11:05:00 PM

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