Happyman reads from Amination/demethylation process Ellis K. Fields
http://www.google.com/patents/about?id=pIQ3AAAAEBAJ&output=text

"SUMMARY OF THE INVENTION

OH 0 OH OCH,

According to the invention, it has now been found that selective demethylation of compounds of the formula (II) can be achieved by treating such compounds

35 with an aluminum halide, such as aluminum chloride or bromide in a homogeneous solution in chlorobenzene, bromobenzene or nitrobenzene, preferably, nitrobenzene, to produce compounds of the formula (I) in high yield and in a single step. The amount of aluminum

40 halide used is not critical and can be from 1 to 20 moles per mole of compound of formula (II), but the best results are obtained with 4—8 moles of aluminum halide. The temperature at which the reaction is conducted can be varied from 0° to 50°C., but the best

45 results are obtained at temperatures of 20°C. or less. Another important advantage of the procedure of the invention is the possibility, owing to the mild conditions employed therein, of using optically active intermediates without any loss of optical activity; thus the separa- tion of optical isomers can be performed, with advantage, at an earlier stage of the synthetic sequence."

This seem feasible? Hypothetically applied to lets say 4-MAR? May I also throw HBr demethylations in there. HBr/NaI is the only I got the patent for.

I have heard of this method but unsure as to why its never employed on Vanillin. Can anyone explain if the aldahyde would interfere here. Eugenol will more then likely have serious polymerisation under these conditions though I would think.

1. Procedure

 In a 5-l. flask fitted with a stirrer, a thermometer reaching to the bottom, a fractionating column about 40 cm. long (Note 1), and a return inlet tube, are placed 912 g. (7.4 moles) of crystalline guaiacol and 1500 g. (1015 cc., 8.8 moles) of 48 per cent hydrobromic acid (p. 26). This apparatus is connected with a condenser, an automatic separator, and an absorption vessel, as shown in Fig. 10 (Note 2). The mixture is gently heated, with continual stirring, at such a rate that the vapor at the head of the column maintains a temperature of 85–95°. The mixture of water and guaiacol which condenses passes through the automatic separator (Note 3), the guaiacol being returned to the reaction vessel and the water collected in the tap funnel, from which it is removed from time to time. The gaseous methyl bromide is collected in an ice-cooled bottle containing a weighed quantity (about 1600 g.) of methyl alcohol (Note 4).
Fig. 10.

After six to seven hours, the temperature at the head of the column begins to rise above 95° and finally reaches 98°, at which point practically no more guaiacol passes over with the distillate. This requires about one hour more, after which the heating is stopped (Note 5). The increase in weight of the absorption bottle amounts to 400–500 g. (57–72 per cent of the theoretical amount of methyl bromide); the water collected weighs 550–560 g. (Note 6).
The residue in the flask, which has become pink in color, is extracted at 85–95° with three 1500-cc. portions of toluene (Note 7), and the united extracts are distilled under reduced pressure on the steam bath until no more moisture passes over with the vapor. The solution (2–2.5 l.) is then allowed to cool, whereupon 385–390 g. of catechol separates in colorless plates melting at 104–105°. The mother liquor is further concentrated under reduced pressure and the residue finally distilled, pure catechol passing over at 124–125° / 12 mm. The distillate, on recrystallization from a small quantity of toluene, yields 8–10 g. of pure material.
The aqueous residue from the three extractions with toluene yields, when the bulk of the water has been distilled off on the steam bath under reduced pressure, a further quantity of catechol by extraction with hot toluene, but the crystals so obtained are contaminated with a red impurity. It is therefore preferable to distil the entire residue, again collecting the fraction boiling at 124–125° /12 mm. and recrystallizing it from fresh toluene. In this way 295–305 g. of pure product is obtained. The forerun contains a little aqueous hydrobromic acid, which may be employed in a subsequent batch. The total yield of pure catechol is 690–705 g. (85–87 per cent of the theoretical amount) (Note .

Reference:http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0149

This yeilds as you can see 85% catechol product from the process. A key saying in the notes means there is a good possibility of "protecting" IE workable modificationof the Pi bond of Eugenol to in effect make this a quick cheep way of demethylating eugenol(or quick way of banning HBr).

Note 8. The reaction appears to be applicable to many other cases where the constitution of the molecule permits of boiling with strong hydrobromic acid.

I think you are going to get side reactions with the aldehyde in vanillin.....I feel there is a thread on this reaction at SM....

Or just do the KOH melt of vanillin to protocatechuic acid - presumably the ester thereof would be soluble in DCM thus alleviating one major issue (provided the ester could survive the basic environment needed), the carboxylic acid moiety would not be prone to further oxidation (thus avoiding the other major problem)... Given that jon has apparently come up with a nice, easy route to propionic anhydride, then presumably methylone would be available via piperonylic acid (3,4-methylenedioxybenzoic acid)?

Propiophenones can be brominated to 2-bromopropiophenones and those can be used to alkylate amines (eg Dimethylamine) to give the correspondent cathinone(s)...

There is already at least one Topic here on the subject (which includes several useful articles) and Brauer shows a route to Cupric Bromide (can't remember which book, 1 or 2 IIRC it is the 2nd)...

Also note - there is at least one paper on using cupric chloride to get to 2-chloropropiophenone (for those with no access to bromine) over at WD if anyone cares to retrieve it... Presumably Brauer's tells us how to make the Cupric Chloride and that the 2-chloropropiophenone will also alkylate amines....

[EDIT] Here is the paper from WD on the preparation of 2-chloropropiophenone by using Cupric Chloride, the solubility of the same in chloroform I have not yet been able to find, so I can't say whether it can be used instead of DMF... What purpose the Lithium Chloride serves has me fucked... Although Wikipedia has a fair bit to say, suggesting it is added to increase the reaction rate - DMF is only there as the solvent - only a polar solvent is needed...

AlCl3