Bandil (Hive Bee)
12-02-01 15:20
No 243261
      4-methyl-2,5-dimethoxyBA via friedel-craft  Bookmark   


Swim had this idea of making 4-methyl-2,5-dimethoxy-benzaldehyde from 2,5-DMBA, utillizing friedel-craft with methyliodide. Is this possible? Would the groups attatched to the benzene rings direct to the correct position on the ring(as the do with bromine)? If it is possible to do with the BA, how about the corresponding alpha-methylPEA? Swim would think that it would be hard to do with that one, because it is a base and would probably separate from the soln. with the HI formed...


(Chief Bee)
12-02-01 16:21
No 243268
      Re: 4-methyl-2,5-dimethoxyBA via friedel-craft  Bookmark   

The lewis acid catalyst needed for the friedel-craft alkylation would probably destroy the 2-methoxy group to some extent. It would also complex with the aldehyde function making the molecule more unreactive, necessitating harsher reaction conditions.

I think it would be a much better idea to reduce 2,5-dimethoxybenzaldehyde to 2,5-dimethoxytoluene with clemmensen or wolff-kishner, and then formylate the toluene using the improved procedure at my page.