cilliersb (Hive Bee)
01-29-02 02:09
No 262236
      P2P from cheap precursors  Bookmark   

Hi Beez

Have any of you tried this synth for P2P from Cinnamyl alcohol? It all seems a bit Strange (or way too easy) to me........

Cinnamyl alcohol (1.30 mm) was dissolved in 75 ml of dry ether saturated with
hydrogen chloride at 0 deg C. Activated zinc dust (5.0 g; 0.076 mol) was slowly
added to the cooled mixture with vigorous stirring at a rate such that the
temperature maintained below 5 deg C. The reaction was exothermic and
considerable hydrogen evolution occurred. The reaction mixture was stirred for
1 hour at 0 deg C and then filtered. The filtrate was shaken with 500 ml of ice
water and then washed to neutrality with aqueous sodium carbonate. The aqueous
washings were dried over sodium sulfate and evaporated under vacuum.
Chromotography of the residual oil over silica gel (Mallinckrodt, 100 mesh,
25 g) using benzene as eluant afforded 60% yield of allybenzene (4 parts) and
propenylbenzene (1 part).
(Hive Prodigy)
01-29-02 03:36
No 262257
      Re: P2P from cheap precursors  Bookmark   

Your title appears to be an ill chosen one. If your product is an alkenylbenzene, how can this be a synthesis for P2P, which is a ketone?

I understand that alkenylbenzenes have a reputation as precursors to certain ketones, but this in itself, is not a ketone synthesis, and thus it is misrepresented by its title.

Yes, I am nitpicking. tongue Other than this, I like the idea. Thank you for sharing. smile


Vivent Longtemps la Ruche!
(Chief Bee)
01-29-02 15:10
No 262444
      Re: P2P from cheap precursors  Bookmark   

What is your reference for this reaction?
(Old P2P Cook)
01-29-02 17:46
No 262520
      Re: P2P from cheap precursors  Bookmark   

If your product is an alkenylbenzene, how can this be a synthesis for P2P, which is a ketone?
Simple, it is a synth of P2P in that the details of the conversion of allylbenzene to P2P are just too trivial to mention. wink
(Hive Prodigy)
01-29-02 17:53
No 262526
      Re: P2P from cheap precursors  Bookmark   

Ok, if that is so, can I only research and detail a synthesis of allylcatechol and call it a synthesis of MDMA, since the methylenation, alkenyl-oxidation, and reductive amination, are all common knowledge? tongue


Vivent Longtemps la Ruche!
(Hive Bee)
01-30-02 00:30
No 262682
      Re: P2P from cheap precursors  Bookmark   

Sorry about the Confusion here guys. The synth is for Allybenzene (4 parts) and propenylbenzene (1 Part).

Interresting that Rhodium asks me for a ref as this is a paragraph from his page.

The ref given there was :A more practical method that is on a preparative scale can be
found in Tetrahedron 27, 5081 (1971).

I assume that the tetrahedron article has more details, but since I don't have this reference material I can't check.

So noone has actually done this?

Maybe I should be the pioneer since Cinnamyl Alchohol does not seem to be watched in "my country"
01-30-02 02:16
No 262703
      Re: P2P from cheap precursors  Bookmark   

The problem is in scaling the reaction up.
Cinnamyl Alcohol Mol Weight 134 therefore 1mm = 134/1000 = .134gms.
The reaction calls for .134 gms in 75 mls Ether or 13 gms in 7500mls and 500 grms activated zinc.
I also once followed up the other reference..Tet 27 5081 and it has nothing to do with this ie wrong ref.
(Hive Bee)
01-30-02 03:44
No 262712
      Re: P2P from cheap precursors  Bookmark   


I see


Brainfart on my part, sorry beez!! This synth will waste more ether than an entire biker colony over the summerlaugh
(Ubiquitous Precursor Medal Winner)
01-30-02 05:57
No 262724
      Re: cheap precursors from Cinnamumble  Bookmark   

Microscale chemistry like this isn't particularly scaleable. 75 ml may have been just a convenient amount of solvent; it does not necessarily indicate that this reaction must bee performed at high dilution. Even the authors themselves, if scaling up, would make do with less than a 57-fold excess of zinc dust.

Monograph number: 2362
Title: Cinnamyl Alcohol.
CAS Registry number: [104-54-1]
CAS name(s): 3-Phenyl-2-propen-1-ol
Additional name(s): cinnamic alcohol; styryl carbinol; gamma-phenylallyl
Molecular formula: C9H10O
Molecular weight: 134.18
Percent Composition: C 80.56%, H 7.51%, O 11.92%
Line Formula: C6H5-CH=CH-CH2OH
Literature references: Occurs (in the esterified form) in storax and in balsam Peru, cinnamon leaves, hyacinth oil. Obtained by the alkaline hydrolysis of storax.
Prepd synthetically by reducing cinnamal diacetate with iron filings and acetic acid; from cinnamaldehyde by Meerwein-Ponndorf reduction with aluminum isopropoxide: Meerwein, Schmidt, Ann. 444, 221 (1925).
Properties:  Needles or cryst mass. Odor of hyacinth. mp 33. d3535 1.0397. bp1.0 72.6; bp5 102.5; bp10 117.8; bp20 133.7; bp40 151.0; bp60 162.0; bp100 177.8; bp200 199.8; bp400 224.6; bp760 250.0. nD20 1.58190; nD33 1.57580.
When small amounts of impurities are present as in the natural article (cinnamyl alcohol from storax), it remains fluid at lower temps than the melting point. Minimum congealing points specified by the Essential Oil Assn are: 33.0 for cinnamic alcohol pure; 28.0 for cinnamic alcohol prime; 20.0 for cinnamic alcohol from storax. Is oxidized slowly on exposure to heat, light and air.
Sol in water, glycerol. Clearly sol in 3 vols 50% alc. Freely sol in alc, ether, other common organic solvents.
Density: d3535 1.0397
Boiling point: bp1.0 72.6; bp5 102.5; bp10 117.8; bp20 133.7; bp40 151.0; bp60 162.0; bp100 177.8; bp200 199.8; bp400 224.6; bp760 250.0.
Melting Point: 33.
Refraction index: nD20 1.58190; nD33  1.57580
USE: In perfumery; as deodorant in 12.5% soln in glycerol.

Now find me one that makes piperic acid into safrole, and I'll bee impressed.

~ ~ ~ C U N D C ~ ~ ~
~ ~ 4 / 20 / 003 ~ ~
1000000 heads high
(Chief Bee)
01-30-02 06:31
No 262732
      Re: cheap precursors from Cinnamumble  Bookmark   

Cilliersb: I don't have my entire webpage memorized wink Especially not the less talked about parts.
(Hive Bee)
01-31-02 06:12
No 263243
      Re: cheap precursors from Cinnamumble  Bookmark   

Sorry about that Rhodium, the last intention I had was to snap at you.

Maybe I'll obtain small quantities and see what the optimum ratio for this reaction is. The numbers given in the article seem a bit sketchy if you ask me.

Thanks for the info 1 1/2 Pint, I also read the MSDS for cinnamyl-OH which contains quite a bit of this info too. The bit that interrested me is the huge number of natural or OTC routes to this comp. It is maybe worth a little more experimentation if you ask me.

Well, time to go stink up my kitchen.

PS: Sorry again Rhodium!