Best route to Phenylacetone?

[Pussy_Kurt]

There are lots of possible routes to get Phenylacetone, i want here to discus two potential methods:

1. Phenylacetic acid + Acetic acid -> P2P (catalyzed with mno2 and heat ~400°C)

2. alpha-methylcinnamic acid -> Bayer-Villiger-Oxidation -> P2P

APAAN is hard to get for me, because Phenylacetonitril is a bitch and sodium is very expensiv. Phenylacetonitril can obtain by oxidative decarboxylation Phenylalanin.

What is your opinion about manufacture P2P in a larger Scale, eg. one mole to 1 Kg? The catalyzed route was an continuous prozess, based to an idea, i am working on self made tube furnance with a catalyst bed. Has anyone experience with this method?

 

[WillD]

Hard
good route, I know it
yes
industrial production goes through phenylacetonitrile as the most commercially viable route.

 

[Zetetic]

Greetings, dear expert!
I have the opportunity to purchase some methylcinnamic acid. It is not considered a precursor here.
I beg you to paint this path for us.
With respect from all of us, young chemists!

 

[UWe9o12jkied91d]

[2] J. Org. Chem., 51,10;1925-1926 (1986)

A stirred slurry of trans-cinnamic acid (111.0 g 0.75 mol) in aceton (515 mL) was treated first with NaHCO3 (274 g 3.26 mol) and then carefully with water (515 mL) The resulting thick mixture was treated dropwise , over 1.5 h, with a soln. of oxone (2 KHSO5 * KHSO4 * K2SO4) (421g, contains 1.825 equiv. of KHSO5) in 4 x 10^-4 M aqu. Na2-EDTA (1610 mL).

During this addition the reaction temperature was maintained at 24 – 27 °C by using a water bath and the rxn pH at ca. 7.4. After the addition was complete the mixture was stirred an additional 0.5 h and cooled to ca. 10°C. The reaction was acidified with conc. HCl (ca. 140 mL) to pH 2 while the temperature was maintained at 10°C and then treated w/ EtOAc (1.0 L) followed by rapid stirring. The mixture was filtered to remove insoluble salts, and the organic layer was removed. The aquaeous layer was extracted with EtOAc (500 mL), and the combined organic layers were washed once with saturated aqu. NaCl (200 mL) dried over MgSO4 and concentrated in vacuo from a 40°C bath. Toward the end of the concentration absolute EtOH was added (to keep the acid from crystallizing out) and concentration was continued until most of the solvent was removed.The yellowish oily residue was dissolved in absolute EtOH (500 mL) cooled on ice and treated with a soln. of KOH (56 g 1 mol) in abs. EtOH (250 mL). The resulting thick slurry was filtered and the solids were washed with EtOH. The filter cake was resuspended in fresh abs. EtOH (750 mL) , filtered, washed with EtOH, and dried in a 50 °C oven to give trans-ß-phenylglycidic acid (139 g 92%) as a white powder.

yield for our target compound was 92 %, rxn time : 2,5 h, scale was 0.5 mol. mp 67-68 (lit: 68-69)

substitute trans-cinamic to methyl cinamic

 

[Zetetic]

Thank you for your reply!