Willgerodt Reaction (phenylacetic acid route)

Elementary · Wed Apr 20, 2005 3:49 pm

I believe the reaction was originally carried out with ammonium polysulphide rather than morpholine and sulphur.

Has anybody got an english translation of C. Willgerodt, Ber. 20, 2467 (1887); 21, 534 (1888) ?

I would also be interested in knowing if styrene can be used as well as acetophenone in the original reaction using ammonium polysulphide.

This reaction would be a nice OTC way of making phenyacetic acid as styrene monomer is easily acquired. Acetophenone would not be too much of a hardship to make either.

ADD ON:-

http://www.orgsyn.org/orgsyn/orgsyn/prepcontent.asp?print=1&showprint=1&prep=CV4P0760

See discussion (phenylacetamide made from acetophenone and ammonium polysulfide)

! Phenylacetamine can be hydrolysed easily to phenylacetic acid)

Would love to have a look at this ref :- Houben, Ber., 59, 2878 (1926).

IndoleAmine · Dreamreader Deluxe

"nice OTC way" involving ammonium disulfide??? Shocked

Polverone · Thu Apr 21, 2005 9:30 am

Ammonium polysulfide can be used with styrene, but it's effective only if you have an autoclave handy. I've tried the variation based on a Chinese patent, posted on the Hive some time back, and didn't get much of anything because I couldn't run it under pressure.

The way I attempted it, after the failure of the first straightforward attempt, was by mixing ethanol, sulfur, and styrene monomer in a jar and adding sufficient Na2S and NH4NO3 to form ammonium polysulfide in situ. This was then capped and left to the attention of the sun's warmth (sealed in garbage bag) for several months. If stinkiness is the measure of success, this worked much better than simply trying to reflux aqueous ammonia, ethanol, sulfur, and styrene like the patent seemed to suggest, but I don't think it worked that well and I don't think it ever will work well without heating under pressure. I did just well enough to make a horrendous stench. The stink clings. I could taste it for a day after working with the crude reaction mixture. I can still smell it faintly on the shirt I was wearing that day and the shirts that were next to it in the laundry basket, though they've been washed 2-3 times now. It smells too bad for me to be eager to attempt other refinements.

I attempted to make a pressure vessel out of water pipe, but preliminary runs with colored alcohol showed that I couldn't get the endcaps to seal tightly enough, even with liberal teflon tape application. Maybe someday, with finely threaded stainless steel pipe...

IndoleAmine · Dreamreader Deluxe

Elementary · Thu Apr 21, 2005 3:17 pm

Thanks Polverone Cool

Another dream that seemed so simple Crying or Very sad

Ammonium Polysulphide OTC you ask :-

Here would be your starting chemicals

Iron wool or filings heated with sulphur (garden centre) = Iron sulphide
Iron sulphide + Acid = Hydrogen sulphide

Household ammonia + hydrogen sulphide = ammonium polysulphide

BTW : Hydrogen sulphide is really poisonous

Nicodem · Thu Apr 21, 2005 7:33 pm

Ammonium polysulphide, (NH4)2Sx, is not ammonium bisulfide, NH4HS.
These are different compounds. And you get ammonium bisulfide by absorbtion of H2S in ammonia. You need also elementary sulphur to make polysulphides from sulphides. You can disolve elementary sulphur in aquoeus sulphide solutions.
example:
Na2S + S => Na2S2
Na2S2 + S => Na2S3
...and so on to higher sodium polysulphides

or you can make it by partial oxidation of the sulphides like Polverone did.

Polverone · Fri Apr 22, 2005 9:08 am

You misunderstand a bit. The stench is not that of hydrogen sulfide from dissociating ammonium polysulfide (though there is some of that too, and of course you must take care not to be poisoned by the sulfides) but of products formed with the styrene. It is a smell unlike anything else I have experienced, and it lasts/clings far longer than inorganic sulfides or polysulfides. I wish I had a pure reference sample of phenylacetamide to figure out if that's what the smell was.

nubee · Master Archiver

im not pretending to have any opinion or know anything about what this thread is trying to work out, but i did a quick look around and found this info:

IndoleAmine · Dreamreader Deluxe

worker · Sat Apr 23, 2005 8:39 am

Working around styrene reactions in industrial fiberglass/epoxy plants had the side effect of not being able to shower enough to not offend the sensitive noses of the men working out in the below ground gyms .Those days of sweat,mold, no ventalation....and they were really agrivated by my aroma

bio · Working Bee

Polverone · Tue Apr 26, 2005 10:26 am

Stick some unwashed mice in the soxhlet, extract for 12 hours with ethanol, and post me a mL. I will try to confirm or deny the mouselike aroma of my reaction products. Say, isn't acetamide described as smelling like mice? This didn't exactly smell like acetamide.

bio · Working Bee

Yes Polverone, you are correct but, no ain't gonna reflux no mice.

However, I did find this little tidbit from Vogel that should also work with the phenyl derivative. Have been wanting to try this method if ever the time is available and saw a procedure recently that uses a sealed appararus at around 200 deg or so with managable pressures (glass was used). Advantage here is no Morpholine needed and NO SMELL at least until it's opened anyway. Time to break out the stainless steel reactor!

Good old Mr. Vogel had this to say...

.....The acetamide often contains a minute amount of.impurity having an odour resembling mice excrement;.............

this can be removed by washing with a small volume of a 10 per cent, solution of ethyl alcohol in ether or by recrystallisation. Dissolve 5 g. of impure acetamide in a mixture of 5 ml. of benzene and 1 • 5 ml. of dry ethyl acetate ; warm on a water bath until all is dissolved and cool rapidly in ice or cold water. Filter off the
crystals, press between filter paper and dry in a desiccator. The unpleasant
odour is absent and the pure acetamide melts at 81°. Beautiful
large crystals may be obtained by dissolving the acetamide (5 g.) in warm
methyl alcohol (4 ml.), adding ether (40 ml.) and allowing to stand....................

I wonder if the awfull smell you described is also an impurity? Would bet that it is, especially since phenyl compounds usually smell better than their aliphatic counterparts.