Another find... let me know if this is already known...
While searching for info re DOM, I discovered a way of methylating 2,5-dimethoxytoluene thats pretty OTC: read this:
Syntheses. (a) 2,5-Dimethoxymethylbenzene
In a dry three-neck 1-L RB flask equipped with a magnetic stirring bar, two stoppers, a reflux condenser, and an Nsub]2[/sub] inlet was placed 2,5-dihydroxymethylbenzene (49.6 g, 0.40 mol). To the flask was added 300 mL of ethanol and the solution was slightly heated with a mantle until the solid dissolved. The heating mantle was then removed, and the solution allowed to cool to room temperature. Over a period of 20 min, DMSO and 100 mL of an aqueous NaOH solution (~10 M) were added to the reaction mixture. The heat released was sufficient to bring the solution to boil. After this step was completed, NaOH (10 g, 0.25 mol) in 10 mL water was added to the solution to make it alkaline. When the boiling subsided, the heating mantle was replaced and the reaction mixture refluxed for 7 h. The reaction mixture was checked by TLC and then transferred to a separatory funnel. The organic fraction was extracted with ether and washed with saturated NaCl solution. The resulting solution was dried with MgSO4, filtered, and then concentrated on a Rotovap. The product was then subjected to flash chromatography. (20% ether, 80% hexane), yielding a light yellow liquid: yield 53.3 g (93.9%)
I read that DMSO, when heated to reflux, disproportionates to dimethyl sulphite, etc, which is a methylating agent. So I wonder, could this method be more generally applicable? Seems like a wondercure to me. Anyone know how this reaction works?
Oh, the ref: Analytical Chemistry, Vol 67, No. 24, Dec. 15, 1995
