Bandil (Hive Bee)
01-27-03 22:03
No 401959
      Trimethyl phosphate methylation of 4-alkyl1,4-DHOB  Bookmark   


Swim attempted to do the dimethylsulfate synth posted on rhodium's page(it uses ethanol, but methanol was substituted and the molar ratios was corrected). The yeild from a double batch was 4 grammes and should have been more like 53 g... Dont know why the yeild was so horrible, but the synth was dropped as it is way to much of a hassle.

Swim was then thinking of using trimethyl phosphate instead, as it is cheap and easily available here :) The compound to be alkylated was 2-methyl-hydroquinone. There has been a report here on the hive where a 70% yeild was reported on hydroquinone. Do you think that equall yeilds is doable on methylhydroquinone?

As far as i could tell from the original patent, aldehyde-phenolic compound's are more readily alkylated than the corresponding phenols. Is it an advantage to convert the methylhydroquinine to 4-methyl-2,5-dihydroxy-benzaldehyde first and then do the methylation?

Thanks alot!

(Hive Adickt)
01-28-03 00:53
No 401997
      DMS  Bookmark   

1: Dimethylsulphate msu bee easy to make, it's an ordinary methylester off sulfuric acid. Iff you mix sulfuric and methanol you get's dimethyether or dimethylsulphat, depending on the temp. (dant have the synt' right here but it must bee at the hive.)
Trimethylphosphate is also a methylation's regent but not so reactive as DMS (remember that all alkylation's regent's is quite toxic) Look up som methylation's with it. (iff you can't find it ill dig it up for you).
Yes methylation off methylhydroquinon goes in high yeald, don't make the aldehyde first, wase of time.