I've been staring at 4-MMC good and long and think I have a viable synthetic route.

From Propylene glycol or Tartaric acid it is an easy step to pyruvic acid.

The acid chloride can be prepared using phosgene (it's over the counter, despite its danger... it's convenient)

There is a patent that shows the friedel craft will happen para and outlines the preparation of cathinones via Friedel craft.

So, in the presence of AlCl3 A friedel craft is performed utilizing toluene.

The last step would be to form the amino group.  I am uncertain whether this would be best accomplished before or after the craft addition.  In the patent I found it is done prior however they utilize a protecting group, I'm reading up more on alternative protecting groups, but think it could be easier to just worry about forming the amine after.

This looks to be very straightforward.  Anyone see any complications?

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6THT-48MY1K8-D&_user=10&_coverDate=06%2F06%2F2003&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1505333638&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=bfad1815454112ec57f6a71e77cb5b86&searchtype=a

"Pyruvic acid is easily prepared in 50+% yield from tartaric acid (over the counter in grocery stores) and potassium bisulfate." - Sauron (science madness)

The way I see it you could go about it a few ways.  One could make chloroform out of bleach and acetone then subject it to heat and UV to get phosgene.

Or the simple reaction CO +Cl2 seems viable.  powdered zinc and some calcium carbonate heat to liberate CO.  Gas with Cl2 gas generated from TCCA or from MnO2 and HCl.

for dealing with phosgene I've heard the best approach is to gas the solution your working with.  Keep the solution on a scale and measure the progress of the reaction by weight difference.  Phosgene is also soluble in toluene, benzene and acetic acid, so it is possible to use a trap to dissolve any excess phosgene you would not want in your immediate environment.

yeah...  I would vote for decomposing chloroform by heating.  More or less thionyl chloride of phosphoryl chloride could be used as well, but I saw phosgene as the easiest to produce and actually handle.  Mostly since it can be generated in a closed system and dissolved in a trap, limiting its exposure to your environment.

I think there might be better production of phosgene from CCl4 which could be prepared from gassing chloroform with Cl2. 

you could just make thionyl chloride from phosgene if you needed a higher bp.

HCl + MeOH does not make MeCl very well and even with a catalyst the yeilds where reported around 30% IIRC from someone over at sciencemadness.

Better to use HBr or NaBr + H⁺ else you will have troubles.