new preparation of phenylacetic acid

[tweekdexter]

swim recently tried this reaction with styrene monomer-sulfer-ammonium hydroxide and ethanol. he put 1 mole of each reagent in a five gallon stainless steel keg. swim installed the lid and placed the keg in a large pot of water and heated it to 95c for 4 hours.  he ended up with a thick burgandy colored product with a strong- strange smell. is this phconh2? does any bee know the correct procedure for this snythesis from start to finnish?

[roger2003]

Patent GB607765

Carboxylic amides are prepared by heating acyclically unsaturated compounds with sulphur and basic trivalent nitrogen compounds which have hydrogen attached to the nitrogen. The unsaturated compound may contain an olefinic or acetylenic linkage and may be a hydrocarbon or may also contain groups such as the ether, ester, ketone, aldehyde, amide, carboxylic acid or alcohol group, and examples are given of many such compounds and also of suitable nitrogen compounds. The reaction may be carried out in an aqueous or organic solvent. The sulphur may be used in the reaction mixture as flowers of sulphur or may be dissolved in the nitrogen base as a polysulphide. Examples are given of the production of (1) phenylacetamide from styrene, aqueous ammonia and sulphur in pyridine; (2) phenylacetamide from phenylacetylene, sulphur and aqueous ammonia in pyridine; (3) phenylacetamide from phenylacetylene and ammonium sulphide-sulphur in dioxane; (4) phenylacetamide from styrene and ammonium sulphide-sulphur in dioxane; (5) phenylacetothiomorpholide from styrene, sulphur and morpholine; (6) phenylacetothiomorpholide from phenylacetylene, sulphur and morpholine; (7) b -phenylpropionamide from 1-phenylpropene-1, sulphur and ammonium sulphide solution in pyridine; ( b -phenylpropionamide from 1-phenylpropene-1, sulphur and aqueous ammonia in pyridine; (9) b -phenylpropionamide from 1-methyl-2-phenylacetylene, ammonium sulphide solution and sulphur in pyridine; (10) n-heptamide from 1-heptene, ammonium sulphide solution and sulphur in pyridine; (11) n-heptamide from 1-heptene, aqueous ammonia and sulphur in pyridine; (12) a -phenylpropionamide from a -methylstyrene, aqueous ammonia and sulphur in pyridine; (13) 2-naphthylacetothiomorpholide from 2-naphthylethylene, sulphur and morpholine and b -(2,4 - dichlorophenoxy) - propiothiomorpholide from 2,4-dichlorophenylallyl ether, sulphur and morpholine-the former may be converted to the corresponding carboxylic acid by hydrolysis in presence of acetic and hydrochloric acids-and (14) 2-pyridylacetamide from 2-vinylpyridine, sulphur and aqueous ammonia in pyridine.

[Aurelius]

go to Rhodium's site and look up the rxn you're interested in.  BTW, you need to use acid or base to hydrolyze the product (red stuff) you've made.

[roger2003]

The procedure described by tweekdexter was published in The-Hive

Post 258134 (missing)

(foxy2: "New preparation of phenylacetic acid", Chemistry Discourse)

and the Chinese patent

Patent CN1110677

uses:

21,7 g
37,6 g
50 ml
30 ml

But my Chinese is too bad, to seee what chemical  is 21,7 g etc.



Phenylacetamide to Phenylacetic acid:

Organic Syntheses CV 4, 760

http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV4P0760

[ning]

Roughly translated:

In a reaction vessel was placed:

Styrene 21.7 g
Sulfur 37.6 g
Ammonia 50 ml
Ethanol 30 ml

Under stirring and heated at 93-95 C for 3-4 hours. Fluids were evaporated from the mixture, it was allowed to cool, and extracted 3 times with 500 ml hot water. The decolorized solution after standing yielded 26.7 g (97%) white sheets having MP of 157-158 C and BP of 280-290. (Phenylacetamide C8H9NO)

100 g of the above phenylacetonitrile and 80 ml HCl were added to 150 ml water and refluxed for 2-3 hours. After cooling to room temp, a precipitate formed and was filtered and recrystallized from 1:2 ethanol/water to yield 84 g (84%) of shining white crystals. (Phenylacetic acid C8H8O2)

If desired, I can try to translate the rest of the patent.

EDIT: Guys, it looks like they're depolymerizing polystyrene to get their styrene. Could this mean meth from styrofoam?  

[roger2003]

They use aqueous ammonia ? percentage ? and ethanol in 95% ?

[ning]

They use aqueous ammonia ? percentage ? and ethanol in 95% ?

They don't say. I guess that's part of the proprietary secret. The ammonia is aqueous, percentage unknown, and I would imagine that a little water in the alcohol wouldn't matter, seeing as how the ammonia is dissolved in water.

Perhaps from stoichiometry it could bee guestimated. I would imagine it would be one of the standard percentages, like 10 or 28 %. My money's on 7 or 10%.

More of the patent:

Preparation of styrene:

A distillation setup was assembled. 100 g powdered scrap polystyrene was added and heated to 340 C or higher. Distillate over 340 C was collected and assumed to be styrene. Still, color was rather crimson, and impure. The impure product was mixed uniformly with 5% by volume sulfuric acid and let stand for 3h to remove impurities, then rinsed 3 times with brine, dried with anhydrous sodium sulfate, added antipolymerization additives. The portion boiling at 145-146 C was collected to yield 89 g (89%) styrene.