uemura (Hive Bee)
11-19-01 22:09
No 238610
      Cinnamic acid reduction  Bookmark   

Uemura has a question. In older times cinnamin acids have been reduced with sodium-amalgane.
Now, can you reduced the double bound using NaBH4? Under standard conditions (i.e. MeOH 0-20DegC)?
Thanks for attention.
Carpe Diem
 
 
 
 
    Rhodium
(Chief Bee)
11-19-01 22:25
No 238614
      Re: cinnamic acid reduction  Bookmark   

I would also be very interested in this. I have also never seen any references to cinnamic acid to hydrocinammic acid using anything else than Na/Hg or catalytic hydrogenation.

Hydrocinnamates are very good starting materials for phenethylamines, using at least three different reaction schemes.
 
 
 
 
    uemura
(Hive Bee)
11-19-01 22:35
No 238619
      Re: cinnamic acid reduction  Bookmark   

Hi Rhod,
thats why I was asking smile Already beesy so early in the morning?
Carpe Diem
 
 
 
 
    terbium
(Old P2P Cook)
11-19-01 23:16
No 238644
      Re: cinnamic acid reduction  Bookmark   

I have also never seen any references to cinnamic acid to hydrocinammic acid using anything else than Na/Hg or catalytic hydrogenation.
Catalytic hydrogenation is so simple and easy that there is no need to look farther - 10% solution of cinnamic acid in ethanol, 1% Adam's catalyst by weight relative to cinnamic acid, room temperature and pressure, hydrogen uptake complete in 8 hours.
 
 
 
 
    Aurelius
(Hive Bee)
11-20-01 01:22
No 238678
      Re: cinnamic acid reduction  Bookmark   

adam's catalyst, composition?

 
 
 
 
    Rhodium
(Chief Bee)
11-20-01 01:47
No 238686
      Re: cinnamic acid reduction  Bookmark   

Adam's Catalyst (Platinum(IV)Oxide, PtO2)

In a fume cupboard, dissolve chloroplatinic acid (H2PtCl6.6H2O, 0.10 g) in water (ca. 0.5 ml) in a porcelain crucible (3-4 cm diameter). Add sodium nitrate (1 g) and evaporate the mixture to dryness, over a low flame, with continuous stirring. Turn the Bunsen burner full on and stir the contents of the crucible vigorously until the mass has melted completely and the initial decomposition has subsided. Keep the bottom of the crucible at a dull red heat for a further 30 min. (too strong a heat decomposes the oxide to the metal). Allow the crucible to cool and wash the contents into a 250 ml. beaker with hot water from a wash bottle. Filter off the brown platinum oxide with a small ('Hirsch') funnel (Whatman paper No. 541) and wash the oxide with hot water (about 200 ml) until the washings are free from nitrate ion. Dry the catalyst over calcium chloride in a vacuum desiccator.
 
 
 
 
    uemura
(Hive Bee)
11-20-01 06:51
No 238772
      Re: cinnamic acid reduction  Bookmark   

terbium
Catalytic hydrogenation is so simple and easy that there is no need to look farther
may be fine and efficient. But what if SWIm doesn't have a hydrogen tank or doesn't want to fiddle around with filled hydrogen ballons and if SWIM doesn't have the adam's catalyst and so on. BUT! SWIM may have dozens of grams of NaBH4. Couldn't he use it. Would it bee worth a try?

Carpe Diem
 
 
 
 
    Rhodium
(Chief Bee)
11-20-01 07:40
No 238781
      Re: cinnamic acid reduction  Bookmark   

NaBH4 together with a transition metal catalyst such as CoCl2 or NiCl2 might do the trick if one does some literature digging, but I have no actual references for this handy.
 
 
 
 
    Rhodium
(Chief Bee)
11-21-01 06:07
No 239086
      Re: cinnamic acid reduction  Bookmark   

Catalytic transfer hydrogenation of cinnamic acid to hydrocinnamic acid using 10% Pd/C and ammonium formate:



http://www.gac.edu/~ghofmeis/chem51/laboratory/transH.html
 
 
 
 
    zooligan
(Hive Addict)
11-21-01 06:32
No 239094
      Re: cinnamic acid reduction  Bookmark   


Hydrocinnamates are very good starting materials for phenethylamines, using at least three different reaction schemes.




Would you care to expound upon this statement, Rhod?

z


"And if we don't get some cool rules ourselves, pronto, then we'll just be bogus too!"
 
 
 
 
    Rhodium
(Chief Bee)
11-21-01 06:42
No 239096
      Re: cinnamic acid reduction  Bookmark   

Check Scheme #9 in ../rhodium/chemistry /mda.dalcason.html

If the alpha-methyl group in the cinnamic acid derivative at the top is replaced with a hydrogen (as in standard cinnamic acid), the products of the Schmidt, Curtius or Hofmann reactions will be regular phenethylamines, and not amphetamine derivatives.
 
 
 
 
    uemura
(Hive Bee)
11-21-01 06:57
No 239098
      Re: cinnamic acid reduction  Bookmark   

Aha, this sounds already bettersmile Thank you Rhod.
Uemura will check next time in the Houben-Weyl and see what he can find in there.
Carpe Diem
 
 
 
 
    Antoncho
(Official Hive Translator)
11-21-01 11:06
No 239145
      Re: cinnamic acid reduction  Bookmark   

This is a little bit off-topic, but, since you brought it up... are you familiar w/this?:
i found it in another russian book scanned and uploaded by our renowned bibliophil Garin



"...Addition of nitrogen dioxide dimer to a double bond runs smoothly, if the latter is activated w/a phenylic ring and a carboxyl. E. g., N2O4 adds to cinnamic acid, forming a,b-dinitrohydrocinnamic acid, which upon subsequent detachment of nitrous acid and decarboxylation gives beta-nitrostyrene w/a preparative yield."




Unfortunately, no details or refs were given. Can someone suggest approximate conditions or search in the literature (PolytheneSam, Foxy2, Megamole?wink) One more worrisome thing for me is if the ring-subst'd things would survive decarboxylation.

I'm not sure if it's of use - are there any other routes to cinnamic acids then via benzaldehydes?

Antoncho
 
 
 
 
    uemura
(Hive Bee)
11-21-01 11:30
No 239153
      Re: cinnamic acid reduction  Bookmark   

Antocho,

are there any other routes to cinnamic acids then via benzaldehydes?

The classical way is the Perkinsche Synthesis : benzaldehyde + Acet-anhydride (+ Na-acetate) -> cinnamic acid
Carpe Diem
 
 
 
 
    Rhodium
(Chief Bee)
11-22-01 03:20
No 239334
      Re: cinnamic acid reduction  Bookmark   

Dihydrocinnamic acid can also be formed by condensation of benzyl chloride with diethyl malonate, followed by ester hydrolysis and decarboxylation. Ordinary malonic ester synthesis reaction conditions apply.

Example references: Korean J Med Chem 3, 142 (1993) and Arch Pharm Res 20, 659 (1997)

 
 
 
 
    PolytheneSam
(Master Searcher)
11-22-01 07:17
No 239380
      Re: Cinnamic acid reduction  Bookmark   

Check the references in these posts for hydrocinammic acids.  Post 238027 (PolytheneSam: "Re: Piperonal ---> MDA", Chemistry Discourse) Post 222968 (PolytheneSam: "Re: The Meerwein Reaction", Serious Chemistry)

>Dimebagoxy......

http://www.geocities.com/dritte123/PSPF.html
 
 
 
 
    otto
(Newbee)
11-22-01 08:51
No 239415
      Re: cinnamic acid reduction  Bookmark   

another way from benzaldehydes is to go via the benzalacetones formed from benzaldehyde and aceton by condensation:

Ar-CHO + CH3COCH3 --> Ar-CH=CHCOCH3

next step would be haloform-degradation:

Ar-CH=CHCOCH3 + Hal2 + OH- --> Ar-CH=CHCOO-
(sorry, no stochiometrics)

hydrogenation can be done already w/ the benzalacetones or with the cinnamic acids. if one uses MEK instead of acetone, one gets upon acidic(!) condensation and after haloform reaction the methylcinnamic acids leading to amphetamines.

otto
 
 
 
 
    Antoncho
(Official Hive Translator)
11-22-01 10:49
No 239446
      Re: cinnamic acid reduction  Bookmark   

otto, you're such a decent bee!wink

as for my question - yes, i know the main route to cinnanic acids is through the BA's, but are there any other (simpler, possibly) ways? Just curious, though.

Antoncho
 
 
 
 
    Ritter
(Master Whacker)
11-22-01 13:07
No 239472
      Re: cinnamic acid reduction  Bookmark   

Organic Reactions vol. 1 has an amazing overview of the Perkin Reaction including numerous examples of different preparations of cinnamic acid derivatives.  The highest yields reported (80-95%)are generated by reacting a substituted benzaldehyde with an equivalent of malonic acid and an equivalent of pyridine as the base catalyst. 

Malonic acid produces superior yields when compared to acetic anhydride.  The only problem is it's somewhat watched because of its use as a barbiturate precursor.

Example:
3,4-Methylenedioxycinnamic acid
45g. of piperonal(0.3 mole), 60g. of malonic acid (.576mol), 120cc. dry pyridine and 3cc morpholine [Note 1]are heated to the reflux point over a 1 hr period then refluxed an additional 20 minutes.  Rxn. mass is cooled and poured with stirring into a mixture of 175cc conc HCl and 300g chopped ice.  The ppt. is collected via vacuum filtration and washed with 25cc portions of HCl and water.  After drying the ppt. melts at 227-230'C and weighs 49-53g (85-90%)

Note 1:  The original procedure calls for the use of  piperidine.  Morpholine was substituted for this carefully watched amine and yields were identical to those in the citation.
 
 
 
 
    Rhodium
(Chief Bee)
11-22-01 13:13
No 239474
      Re: cinnamic acid reduction  Bookmark   

The Willgerodt reaction is also a route to Hydrocinnamic acids:

Reflux a mixture of 53.5 g of propiophenone, 20.5 g. of sulfur and 46 g (46 ml) of morpholine for 6 hours. Pour the reaction product into 400 ml. of 10% alcoholic sodium hydroxide solution and reflux for 7 hours. Distill off the alcohol, dilute with water, acidify with hydrochloric acid, and extract three times with ether. Wash the ether extracts with water, dry, remove the ether and distil. Collect the hydrocinnamic acid at 125-129C/6 mmHg, it solidifies completely on cooling, mp 46-47C. The yield is 39 g.

Ref: Vogel, "Practical Organic Chemistry" 3rd Ed, p925
 
 
 
 
    Ritter
(Master Whacker)
11-26-01 19:02
No 241052
      Re: cinnamic acid reduction  Bookmark   

Rhodium:

I found two reductions of cinnamic acid for you:

Nickel-Aluminum alloy in 10%NaOH at 90-100'C (80-95% yields)
Org. Synth. Col. Vol. 4  p 136
J. Chem. Soc. 1948, 999

Saturation via chromous sulfate:
JACS 1966, 88, 4964
 
 
 
 
    Rhodium
(Chief Bee)
11-27-01 00:16
No 241155
      Re: cinnamic acid reduction  Bookmark   

Thank you. The Org. Syn. ref can also be found here: http://www.orgsyn.org/orgsyn/prep.asp?prep=cv4p0136

beta-(o-Carboxyphenyl)propionic acid

In an open 1-l.wide-mouthed round-bottomed flask are placed 18 g. (0.094 mole) of o-carboxycinnamic acid and 550 ml. of 10% sodium hydroxide solution. The mixture is warmed to 90C (Note 8) on a steam bath and stirred mechanically. The steam bath is then removed while 54 g. (Note 9) of nickel-aluminum alloy (Raney catalyst) powder is added through the open neck of the flask in small portions (from the end of a spatula) at frequent intervals (Note 10). When addition of the alloy is complete (about 50 minutes), the mixture is stirred and maintained at 90-95C for 1 hour by warming on a steam bath. Distilled water is added as needed to maintain the total volume at approximately 550 ml. The hot mixture is filtered with suction, and the metallic residue is washed with 50 ml. of hot 10% sodium hydroxide solution and two 50-ml. portions of hot water in such a manner that the solid is always covered with liquid (Note 11). The cooled filtrate and washings are added dropwise with mechanical stirring to 300 ml. of concentrated hydrochloric acid (sp. gr. 1.19) in an open 2-l. beaker at such a rate that the temperature does not exceed 80-85C (Note 12). Separation of crystalline material begins almost immediately and is complete when the beaker contents have cooled to room temperature. The beta-(o-carboxyphenyl)propionic acid is separated by suction filtration, washed with water, and air-dried (Note 13). The yield is 16.8-17.3 g. (92-95%), m.p. 165.5-167C (Note 14).

Notes:

8. It is advisable to insert a thermometer only at intervals since the alkaline mixture attacks glassware to an appreciable extent on prolonged contact.

9. Using less than 50 g. of the alloy results in the same yield of final product, which, however, contains small amounts of unchanged o-carboxycinnamic acid. Equally good results are obtained when proportionately smaller quantities of reactants are used.

10. If excessive foaming is encountered it may be controlled as required by the addition of a few drops of octyl alcohol.

11. The metallic residue may ignite if allowed to dry on the filter. Disposal can be carried out by dissolving the residue in dilute nitric acid. (Caution! Vigorous reaction.)

12. With this order of addition, aluminum salts remain in solution, thus simplifying the procedure. External cooling may be applied in order to save time.

13. Extraction of the filtrate with ether gives an additional 0.4-0.5 g. of the crude acid after removal of solvent by distillation. It may be purified by conventional means to give an additional 0.25-0.35 g. of the pure product.

14. beta-(o-Carboxyphenyl)propionic acid may be recrystallized from hot water (about 20 ml./g.), giving material m.p. 166.5-167.5C.
 
 
 
 
    Rhodium
(Chief Bee)
01-08-02 14:03
No 254130
      Re: cinnamic acid reduction  Bookmark   

3-(4-Nitrophenyl)propanoic acid

A suspension of 4-nitrocinnamic acid (13.5 g, 70 mmol) in H2O (100 mL) was treated with hydroxylamine sulfate (18.5 g, 113 mmol) and
hydroxylamine-o-sulfonic acid (43.5 g, 385 mmol) at 0C. The pH was adjusted to 7.6 with 50% NaOH, and additional base was added as
needed over the next 6 hours to maintain a pH of 7.6. The mixture was then filtered, and the filtrate was acidified to pH 2 with 2N H2SO4.
The solids that formed were filtered, washed with H2O, and recrystallized from EtOH:H.sub.2 O (30 mL:150 mL) to give the title compound.

Ref: US Pat 6,046,355 (Example DD)


Just HOW does this work? Cinnamic acid that usually only can be reduced by H2/Pd, Na/Hg or electroreduction suddenly can be reduced by hydroxylamine derivatives?