When doing a vanillin demethylation, what other chemicals can one substitute the Pyridine, triethylamine? Can I use aniline?
I understand microwaving is the way to go on demethylation.
Can one microwave the following methylation with DCM+base, or will MW* have a disruptive effect on the methylation like it does on the Vilsmeier?
https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#pyralcl3 (https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#pyralcl3)
Anhydrous AlCl3 (9.7 g, 0.0724 mol) was suspended in a solution of 10g (0.0658 mol) of vanillin in 100 ml of methylene chloride in an apparatus protected from atmospheric moisture. While stirring briskly and cooling to maintain the temperature at 30-35°C, 22.9g (0.290 mol) of pyridine was added slowly. The reaction was vigorous; the resulting clear light orange solution of the reaction complex was heated to reflux (45°C) and maintained at that temperature with stirring for 24 hours. The solution, which had darkened only slightly during the reflux period, was cooled to 25°C and the product was hydrolyzed, while stirring and maintaining the temperature at 25-30°C, by the addition of dilute (15-20%) HCl until the mixture was definitely acidic to congo red indicator. Of the two phases present at this time, the lower methylene chloride layer contained most of the small amount of the unchanged vanillin, and essentially no protocatechuic acid, the latter was dissolved in the aqueous phase. Evaporation of the methylene chloride yielded 0.8 g of vanillin. Extraction of the aqueous phase with ether followed by evaporation of the ether left 7.9 g (87%) of pale yellow crystals of protocatechualdehyde melting at 153-154°C.
Using the cheaper triethylamine in place of pyridine lowered the yield to 61.5%
You have this pyridine hydrochloride procedure: https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#pyrhcl (https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#pyrhcl)
It is exemplified for eugenol, but I assume you can see the obvious similarities to vanillin.