enima - 8-3-2005 at 00:45
Hi,
I'm wondering if it would be possible to hydroxymethylate 1,4-dimethoxybenzene (or 2-halo-1,4-dimethoxybenzene) to the corresponding benzyl
alcohol using either an acid or base catalyzed hydroxymethylation.
enima - 10-3-2005 at 08:15
An oxidiative hydroxymethylation perhaps?
Synlett 2004, No. 9, 1575-1576.
In a typical procedure 10 mmol arene, 3 g (100 mmol) paraformaldehyde, 0.25 mg (0.0025 mmol) H2SO4 and 4.54 g (20 mmol) DDQ were stirred in 10 mL
acetonitrile
for 5 hours at 80 °C. The reaction mixture was cooled to room temperature. The precipitate formed was filtered and washed twice with EtOAc. The
product from the iltrate and wash was purified by flash chromatography.
The results for some exemplary substrates are presented in Table 1.
Yield for 1,4-dimethoxybenzene is 89%.
My idea is to modify the synthesis and use a similar mechanism. DDQ is very expensive.
Maybe using something like SIBX (Stablilzed O-Iodoxybenzoic acid) instead of DDQ.
If oxone is used you can yield the benzoic acid. (Reduce this to the alcohol)
Another Idea I have is forming the benzylbromide via bromomethylation and then hydrolysis with an NaOH solution
[Edited on 10-3-2005 by enima]
[Edited on 10-3-2005 by enima]