ninhydric1
Hazard to Others
Posts: 345
Registered: 21-4-2017
Location: Western US
Member Is Offline
Mood: Bleached
|
|
ninhydrin synthesis
Is there any feasible way of synthesizing ninhydrin? I desire it for fingerprinting and the Kaiser test, but I haven't found any viable syntheses. If
it is possible, I would prefer that the chemicals required are OTC.
|
|
|
clearly_not_atara
International Hazard
Posts: 2691
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
https://archive.org/stream/p2journal97chemuoft#page/1440/mod...
It appears that ninhydrin results by the double nitrogen insertion of 1-indanone by nitrosodimethylaniline in the presence of KOH, followed by acidic
hydrolysis. If I'm reading this right.
I think nitrosodimethylaniline can be made by the nitrosation of dimethylaniline with nitrous acid or something similar. However, production of
anilines is hard.
[Edited on 23-4-2017 by clearly_not_atara]
|
|
|
CuReUS
National Hazard
Posts: 928
Registered: 9-9-2014
Member Is Offline
Mood: No Mood
|
|
you could make it in 3 steps
1.One pot conversion of phenylalanine to phenylpropionitrile followed by hydrolysis to give phenylpropionic acid -https://www.google.co.in/url?sa=t&rct=j&q=&esrc=...
2.intramolecular cyclisation of phenylpropionic acid to 1-indanone using
a)Conc H2SO4(lot of side products though)- http://pubs.rsc.org/-/content/articlelanding/1968/j2/j296800...
b)a better method is by using PPA(if available OTC) - https://www.thieme-connect.com/products/ejournals/abstract/1...
3.conversion of 1-indanone to ninhydrin - "Tatsugi, Jiro; Izawa, Yasuji Journal of Chemical Research, Miniprint, 1988 , # 11 p. 2747 - 2763"
|
|
|
Boffis
International Hazard
Posts: 1836
Registered: 1-5-2011
Member Is Offline
Mood: No Mood
|
|
There is also a synthesis in Vogel 3rd edition which if I recall correctly is from phthalic anhydride via 1,3-indandione.
|
|
|
AvBaeyer
National Hazard
Posts: 644
Registered: 25-2-2014
Location: CA
Member Is Offline
Mood: No Mood
|
|
Or you could just buy it. It is available on Amazon. Saves time.
AvB
|
|
|
CharlieA
National Hazard
Posts: 645
Registered: 11-8-2015
Location: Missouri, USA
Member Is Offline
Mood: No Mood
|
|
Buying is definitely easier and faster and cheaper.
Robert Bruce Thompson, in his Supplement to his book, Illustrated Guide to Home Chemistry Experiments, gives a synthesis of ninhydrin from aspirin.
Aspirin is hydrolyzed to salicylic acid, which is decarboxylated to phenol, which is reacted with phthalic anhydride to give ninhydrin. I think I may
have seen a thread on this forum to produce phthalic acid from PETE (soda bottles, water bottles, etc.), which can then be dehydrated to phthalic
anhydride.
All in all, I can't imagine how much it would cost to synthesize ninhydrin by this route, nor do I know how many other OTC chemicals would be
involved. It would certainly be a great learning experience involving much time, effort, glassware and chemicals. If you attempt this, good luck and
let us know how it turns out!
|
|
|
clearly_not_atara
International Hazard
Posts: 2691
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
How does the reaction of phenol with phthalic anhydride give ninhydrin? I assume phenol must be destroyed by the reaction but I'm not sure how to
write it. It seems like the product would just be monophenyl phthalate.
CuReUS: the chlorination of phenylalanine does not produce phenylpropionitrile, rather phenylacetonitrile.
Cinnamic acid can be obtained from cinnamon and reduced to 3-phenylpropanoic acid which cyclizes to indanone with strong Brønsted acid.
I think it might be possible to use nitrosobenzene to replace nitrosodimethylaniline in the original synthesis of ninhydrin. The latter is easier to
prepare if you can buy dimethylaniline since it requires only reacting this (spontaneous) with an alkyl nitrite. The preparation of nitrosobenzene is
more involved but requires only nitrobenzene, zinc, ammonium chloride, and sodium dichromate:
http://www.orgsyn.org/demo.aspx?prep=CV3P0668
If nitrobenzene is unavailable, nitrotoluene may be a suitable replacement. That's as OTC as it's gonna get I'm afraid.
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
Quote: Originally posted by CharlieA  | | I think I may have seen a thread on this forum to produce phthalic acid from PETE (soda bottles, water bottles, etc.), which can then be dehydrated to
phthalic anhydride. |
I'm pretty sure that'd be terephthalic acid (para), not phthalic acid (ortho). It's about $0.20/g to buy phthalic acid via mail-order and doesn't
seem to have any special controls on it. P2O5 is available for a lot of people, at quite a reasonable price, and can dehydrate acids to their
anhydrides. Phthalic acid can be dehydrated to its anhydride just by heating it, but not acetic acid, which you also need, apparently. Phthalic
anhydride can be reacted with acetic anhydride to give some crazy chemical that somehow reacts with sodium methoxide to replace the oxygen in phthalic
anhydride with a methylene bridge. Once there, it's just a matter of oxidizing the methylene bridge with selenous acid, which is a reaction I'm more
familiar with. I guess if all those things are accessible, this paper might be interesting:
Attachment: ninhydrin.pdf (1.1MB)
This file has been downloaded 455 times
[Edited on 4/24/17 by Melgar]
|
|
|
CharlieA
National Hazard
Posts: 645
Registered: 11-8-2015
Location: Missouri, USA
Member Is Offline
Mood: No Mood
|
|
clearly_not_atara: Two moles of phenol react with one mole of phthalic anhydride to yield one mole of
phenolphthalein, with heat in the presence of sulfuric acid, according to Robert Brent Thompson. I don't know the mechanism. 2 moles of PhOH replace
one of the carbonyl oxygen atoms of the phthalic anhydride.
Melgar: of course you are right. My bad! I can only plead the infirmities of old age (as I do so often).
|
|
|
Cryolite.
Hazard to Others
Posts: 269
Registered: 28-6-2016
Location: CA
Member Is Offline
Mood: No Mood
|
|
@atara: What about using nitrosophenol instead of NDMA? Its synthesis is similarly straightforward, and it seems like it would also work for the
oxidation of indanone.
However, another question is how to best synthesize indanone. The most natural route to my mind is the acid catalyzed intramolecular Friedel Crafts
with hydrocinnamic acid, but what is the most natural way to make this? The hydrogenation of cinnamic acid with precious metal catalysts is
straightforward, but not everyone has the equipment to carry this out. Further, what is the easiest way to make even cinnamic acid? There are methods
which start from benzaldehyde (annoying), but the easiest precursor is cinnamaldehyde as mentioned. But even converting this to cinnamic acid is
annoying! Most off-the-shelf oxidizers will overoxidize, and although leaving cinnamaldehyde on air converts it to the acid, it also overoxidizes a
portion to benzoic acid and also coproduces some weird epoxide side products.
|
|
|
Boffis
International Hazard
Posts: 1836
Registered: 1-5-2011
Member Is Offline
Mood: No Mood
|
|
If you are going to use indanone you will need more than condensation with an aromatic nitroso compound. This reaction is applied to indan-1,3-dione
and you could probably replace the aromatic nitroso compound with an alkyl nitrite. The nitroso compound condenses with the reactive methylene group
between the two carbonyl groups to give an imine that is then hydrolysed to aniline and a carbonyl group. The new, central, carbonyl function then
reacts with water (in a similar fashion to chloral giving chloral hydrate) to give the trione hydrate (gem-dihydroxy group). It may be possible to do
this with an alkyl nitrite and gaseous HCl or conc hydrochloric acid and as in the preparation of 2,3-butadione-monoxime from butanone, if this
reaction works then the product would be the 2-oxime of indane-1,2,3-trione which on acid hydrolysis would give ninhydrin.
BUT you still need to get to the dione. There are probably many routes but the one described in Vogel (and incidentally Melgars link too) is the
simplest route and it starts with ORTHO phthalic anhydride. The acid from PET is terephthalic acid which is the PARA (ie 1,4) benzene dicarboxylic
acid and it doesn't form an anhydride. The synthesis from 1-indanone is likely to be complex and multi stage so all this talk about hydrocinnamic acid
etc is rubbish. If you are going to use the nitroso oxidation route rather than the selenium dioxide one, why try an use anything other then
nitrosodimethylaniline? Its preparation is insanely simple and it is unlikely that nitrosobenzene or nitrosophenol will give better results or are
less toxic. Most of the contributors above simply haven't bother to even check out what they are trying to prepare.
|
|
|
CuReUS
National Hazard
Posts: 928
Registered: 9-9-2014
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Cryolite. | | The most natural route to my mind is the acid catalyzed intramolecular Friedel Crafts with hydrocinnamic acid, but what is the most natural way to
make this? |
cinnamic acid can be reduced to hydrocinnamic using Na amalgam or even amalgamated Zn/HCl -https://en.wikipedia.org/wiki/Phenylpropanoic_acid#Preparati... (the wiki page also gives a ref for the intramolecular FC to indanone)
There is a way from phenylalanine,but it gives lots of side products - http://www.sciencedirect.com/science/article/pii/S0926860X10...
also can phenylalanine be diazotised/reduced using hypophosphorous acid or sodium stannite to give hydrocinnamic acid ?If the former works,then one
could do a one pot reduction cyclisation of phenylalanine to indanone using 1 mole phenylalanine and 0.5 moles of hypophosphorus acid.
0.5 mole phenylalanine + 1 mole NaNO2 + 0.5 mole H3PO2 >>0.5 mole phenylpropanoic acid + 0.5 mole
H3PO3
the 0.5 mole phosphorus acid formed from hypophosphorus again reduces the remaining 0.5 mole of phenylalanine diazonium to phenylpropanoic acid(albeit
slowly -http://pubs.acs.org/doi/abs/10.1021/ja01132a036) and itself gets oxidised to phosphoric acid which then catalyses the intramolecular FC.
[Edited on 25-4-2017 by CuReUS]
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
