Author Topic: Phenyl Ethyl Piperidone 4 (NPP)  (Read 25928 times)

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  • Guest
Phenyl Ethyl Piperidone 4 (NPP)
« on: November 10, 2004, 06:40:00 AM »
I thought you would all find this interesting:

 "and 1-(2-phenylethyl)-4-piperidone, which was synthesized from phenethylamine and methyl acrylate, followed by a Dieckmann condensation and decarboxylation"

Interesting huh?



  • Guest
more interesting would be your source for this
« Reply #1 on: November 10, 2004, 08:50:00 AM »
more interesting would be your source for this information.



  • Guest
nothing new here..
« Reply #2 on: November 10, 2004, 12:28:00 PM »
nothing new here..

Alpha- and Beta-Prodine Type Compounds
A. H. Beckett, A. F. Casy, G. Kirk;
J. Med. Chem.; 1959; 1(1); 37-58.

rxn between acrylic acid ester and beta-phenethylamine..


Ethyl acrylate (300 g) was added with stirring to 2-phenylethylamine (121 g) in dry ethanol (200 ml) and the mixture refluxed for 48 h. The product was fractionally distilled under reduced pressure to give N-di-(2-carbethoxyethyl)-2’-phenylethylamine (303 g) as a colourless oil, b.p. 166-168’ (0.3 mm)

Dieckmann condensation..

N-2’-phenylethyl-4-piperidone ethylketal.

N-Di-(2-carbethoxyethyl)-2’-phenylethylamine (70 g) was added to a stirred suspension of bird shot sodium (10.8 g) in xylene (250 ml) and the mixture, protected from moisture, warmed to 50’ to initiate the reaction. A further quantity of base was then added drop-wise at a rate sufficient to maintain the reaction. Stirring was continued for 3 h after addition of the base, the mixture cooled, and water (250 ml) added drop-wise. The aqueous phase was separated, washed with ether (2 x 100 ml), and acidified with concentrated hydrochloric acid (congo red). The solution was saturated with anhydrous potassium carbonate and the yellow oil which separated extracted with ether (600 ml). After drying (K2CO3), the ether was evaporated to give crude N-2’-phenylethyl-3-carbethoxy-4-piperidone (103 g). The ketone was refluxed with aqueous 20 per cent hydrochloric acid (450 ml) for 3.5 h (negative reaction with ferric chloride). The product was evaporated to dryness under reduced pressure, the free base liberated with aqueous 25 per cent sodium hydroxide and extracted with ether. After drying (Na2SO4), the ether was evaporated and the residue treated with excess of alcoholic 10 per cent hydrochloric acid. The crystals (42 g) which separated were collected, the free base liberated with aqueous ammonia and extracted with ether. The ether was dried (Na2SO4) and the ether evaporated to give N-2‘-phenylethyl-4-piperidone ethylketal (35 g) as a pale yellow oil which could not be distilled. It gave a hydrochloride. needles from ethanol, m.p. 178-179' dec. The ketal gave a picrate, needles from ethanol, m.p. 136-137' dec.

and finally, decarboxylation..

A mixture of N-2'-phenylethyl-4-piperidone ethylketal (20 g) and dilute aqueous hydrochloric acid (150 ml) was refluxed for 2 h. cooled aid washed with ether. The free base was liberated with aqueous ammonia and extracted with ether. After drying (Na2SO4), the ether was evaporated and the residue (13.0 g) crystallized from light petroleum (b.p. 80-l00') to give N-2'-phenylethyl-4-piperidone (12.1 g), needles. m.p. 60.5-61.5'.


  • Guest
« Reply #3 on: November 11, 2004, 05:32:00 PM »
Is there any difference between "bird shot sodium" and Sodium metal?