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asilentbob
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p-DCB
While it might not be the most practical solution to getting rid of at least one of chlorines on p-DCB (and replacing it with a hydrogen), Grignard
reagent formation and subsequent water hydrolysis is an option... Since Grignards are really strong bases. Di-Grignard formation is also an option.
Also reacting the reagent with other things presents further possibilities.
Google books - Handbook of Grignard Reagents pg.69 by Gary Silverman S Silverman - 1996 - 708 pages
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"In earlier work, only one halogen atom of dichloro derivatives of benzene and naphthalene reacted with magnesium [60], and the chlorine of
p-chlorobromobenzene was completely unreactive [61]. By using this method, a 100% yield was obtained of the mono-Grignard and a 10% yield of the
di-Grignard of p-chlorobromobenzene in 15 min at room temperature. After 2 hr the yield of di-Grignard was 100%. With p-dichlorobenzene the yield of
di-Grignard was 30% in 2 hr. Use of a lower Mg/halide ratio permitted the rapid and selective formation of the mono-Grignard of p-dichlorobenzene,
which was converted to 4-chlorobenzoic acid in 89% yield by CO2 quench."
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The table on p.69 is also particularly relevant.
This could be ok if one has access to lots of scrap Mg... The grignard reagent formation would also be very sluggish with normal Mg and not the highly
reactive "Rieke" Mg... If it worked appreciably at all. It might just take a really long formation time.
Hopefully this info is useful.
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Rosco Bodine
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Actually , now that you have pointed out selective reduction of the one chlorine by way of a grignard
reaction .....not to diss your idea at all , it gives me another idea . In the beginning of this thread of course
benzene itself was synthesized , because of the relative
difficulty of obtaining benzene since it is almost become a banned material due to its carcinogenic properties .
Instead of a somewhat awkward grignard method
for selectively stripping one of the chlorines , why not
just use aluminum amalgam and strip *both* of the
chlorines from moth crystals as an expedient source of benzene ?
The aluminum amalgam in isopropanol readily forms
aluminum isopropoxide which is a damn active reducing agent , and should readily tear *all* the chlorine from just about anything , including para-DCB
.
Update:
It has already been tried by Polverone , and no joy
using the aluminum amalgam . See the bottom of page 3
http://www.sciencemadness.org/talk/viewthread.php?tid=916&am...
That resistance to any reaction pretty well rules out any other contemplated condensations or other reactions
involving the chlorines of paradichlorobenzene , as it is
inclined to sit there and defy any reaction of its chlorines .
So for any of our desired purposes paradichlorobenzne
is pretty much definitively worthless .
[Edited on 26-4-2007 by Rosco Bodine]
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Nicodem
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| Quote: | Originally posted by chemoleo
I certainly like the idea of such a condensation.
I was however under the impression that paradichlorobenzene is extremely unreactive - Nicodem, the procedure you cite, is that specific for PDCB or a
generic protocol for chloro aromatics? |
Do you mean the Ullmann reaction on p-dibromobenzene? Well, that works on dibromo, but to make it work on dichloro like in the attached scheme would
be very difficult (see explanation in the post). Ullmann reactions do proceed on chloroaromatics, but only in certain cases in certain conditions.
Otherwise, the reaction requires a polarizable halogen, which F absolutely is not, while Cl can't really be considered much polarizable in comparison
with Br or I. This however does not mean p-dichlorobenzene would necessarily be impossible to use. It just mean than one would need to find the
optimum conditions: higher temperature, efficient cosolvent, best possible Cu ligand, etc. Someone should try it out.
If nothing else, p-dichlorobenzene can be coupled with alcohols under the conditions that allow the benzyne intermediacy (the aromatic
elimination/addition mechanism). But the conditions required are truly extreme and besides the product would be a mixture of regioisomers.
| Quote: | Originally posted by Rosco Bodine
That resistance to any reaction pretty well rules out any other contemplated condensations or other reactions involving the chlorines of
paradichlorobenzene , as it is inclined to sit there and defy any reaction of its chlorines .
So for any of our desired purposes paradichlorobenzne is pretty much definitively worthless . |
It is the mechanism of the reaction that determines what can be done and what not. If one substrate is non-reactive in one mechanism this says nothing
about its reactivity in other mechanism. As you see a couple posts above, p-dichlorobenzene is reactive in the Mg insertion reaction, but this says
nothing about its reactivity, for example, in SN2 reactions. EtCl also reacts with Mg to form a Grignard reagent and is also very reactive in SN2
substitutions, but chloroaromatics like our substrate here are absolutely unable to work in SN2 substitutions. As you see you can not draw conclusions
from one example to the other unless you are aware of the reaction mechanism.
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Axt
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| Quote: | Originally posted by Rosco Bodine
On the far right side of the equations there you show a byproduct of 2 HCl , and it looks like it should be
just 1 HCl . |
Yeh that'd be another error. I made them by copying and pasting together in ms paint, forgot to delete the "2". Probably should be written as NaCl
anyways.
This probably has swayed off topic a bit, though "Derivatives of Nitrochlorobenzenes" definately deserves a topic of its own, out of prepublication.
Another idea I entertained was the condensation of the sodium salt of nitromethane with DNCB, with the target being "nitro-TNT"  Though this presented solvent problems as well.
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Rosco Bodine
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| Quote: | Originally posted by Axt
This probably has swayed off topic a bit, though "Derivatives of Nitrochlorobenzenes" definately deserves a topic of its own, out of prepublication.
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Rest assured I have no wish to broaden the discussion
to all of those possibilities . If this goes too far afield on an irrelevant tangent , the topic can be split . Please hold off on such topic
cleansing though as I am about to connect the dots which ties some of this peripheral discussion together .
Aside from the benzene to DNCB route , my interest in a parallel is directed again to the possibility of chlorinating naphthalene which was said to
also predominately result in a single monochloro product , and subsequently nitrating that to a dinitro or trinitro monochlorinated naphthalene
intermediate , which could be condensed with ethanolamine ,
and then nitrated to form a polynitronaphthyl analogue of
pentryl . To explain / justify my curiosity about naphthalene ,
If you look at the promotion of nitration on the benzene ring
of the precursor for pentryl , that is the condensation product from DNCB , you can see that there is considerable
greater ease for introduction of that third ring nitro , than for
say the conversion of ordinary dinitrobenzene to trinitrobenzne . Indeed it is trinitrated with little more difficulty than converting dinitrophenol
to picric acid . So
it is evident that ethanolamine substituent greatly promotes nitration on a benzene ring . If that same promotion of
nitration occurs on a naphthalene ring , then the naphthalene could also go to a higher level of nitration much more easily , for example to the
tetranitro ...which might
produce an explosive that is susbstantially the equivalent
of pentryl , while eliminating the requirement for first obtaining benzene since naphthalene is OTC .
The scheme involving TRIS could also be applicable here ,
as could the condensations with non-amino alcohols and
glycols , and polyols .
| Quote: |
Another idea I entertained was the condensation of the sodium salt of nitromethane with DNCB, with the target being "nitro-TNT" Though this presented solvent problems as well. |
Well you proved already that the solvent may not be so
much of a concern , if the DNCB is going to be preferential
in its reactivity towards whatever is dissolved in that
solvent . Whether this holds true in every case , who knows , but trying different solvents is easy enough .
About that bis-aromatic byproduct as occurs when the
amino hydrogens both attach to an aromatic , instead of
the single substitution which is desired ......I wonder if that
can be minimized or even eliminated by changing the order of addition or temperature or pH , or if it is just inevitable
that a certain percentage of the byproduct is going to
occur by pure chance .
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Axt
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Something like DMSO would be needed for sodium methylnitronate condensation with DNCB as its insoluble in organics and reacts with water producing red
polymeric crap. I didn't have anything that would work.
Indeed derivartives of naphthalene would be something to look at. Idealy you would want 1,8- or 1,5-dichloronaphthalene but achieving that would mean
sorting through a messy mix of isomers, so using the TCCA route to form a monochlorinated 1-chloronaphthalene would probably be the cleanest starting
point with the target C12H7N7O13.
The attachment looks to put a nail in the coffin for p-DCB, at least as an precursor to any useful pentryl analogue. It studies the isomers produced
on nitration, and the products of condensation with ammonia. None of which look interesting. Spending time on converting these to anything useful
would best be spent working on producing 1-CB, 1,3-DCB or 1,3,5-TCB.
1,3,5-trichlorobenzene, whose pentryl analogue (nonyl) should be accessable enough .. sodium benzoate -> benzene -> nitrobenzene -> aniline
-> trichloroaniline -> trichlorobenzene -> dinitrotrichlorobenzene -> dinitrophenyltris(aminoethanol) -> nonyl. OK, it looks much more
attractive if you were able to start from aniline. Nonyl's calculated properties place it in the class of RDX, according to http://www.sciencemadness.org/talk/viewthread.php?action=att... .
Regarding the bis(dinitrobenzene) byproduct, it looks like a lot more was produced in the picture then there actually was, being fine and brightly
coloured it stands out but there was less then 3 grams isolated.
[Edited on 1-5-2007 by Axt]
Attachment: THE DINITRO DERIVATIVES OF PARA-DICHLOROBENZENE.pdf (829kB)
This file has been downloaded 2225 times
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Rosco Bodine
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From all I have found in the literature so far , it appears
that DNCB is the only viable compound for condensations
which occur under ordinary conditions , not requiring high pressures and high temperature autoclave conditions.
DNCB is also the simplest and cleanest of the aromatics
that can be easily obtained in good yield for one isomer ,
starting from the aromatic , chlorinating and then nitrating .
There was only one naphthalene derivitive I could find that
was a possible analogue , the 1,4 chloronitronaphthalene
produces similar condensations as DNCB , but requires autoclave conditions . US675434 describes some others
up to a condensate where the bromine of bromotetranitronaphthalene is substituted and references some past century Berichte articles for this .
Evidently
the mechanism I was contemplating does occur with naphthalene , but not nearly so readily as it occurs for
the single DNCB benzene ring , at least for the mononitrochlorinated naphthalene . Also it seems the stability of the chlorinated and nitrated
naphthalenes is
not nearly as good as DNCB , which one would suppose means they would be easily reactive , but seems to
be contradicted by the use of autoclave reactions .
So for reasons of difficult reactivity for the alternatives ,
and many more steps making the analogues impractical ,
because of the mixed isomers and more extreme conditions ,
the alternatives are pretty much ruled out as impractical ,
on both counts , PDCB or naphthalene , as both run into problems which complicate those synthetic routes beyond
practicality .
DNCB is really the only way to go on these sorts of condensations for a lab scale process . The only
likely valuable analogues of pentryl are going to
be derived likewise from condensations involving DNCB ,
the variation being with the aminoalcohol used .
If the idea which you had about condensing TRIS with
DNCB did work to form a "heptryl" sort of compound ,
It would not surprise me if it surpassed RDX . It also
wouldn't be any huge surprise if it turned out to have
stability problems , or if it was flame sensitive like HNI ,
or could even be a primary explosive .
Axt , could you post that NONYL file as regular pdf attachment , as that link is hanging when I try to open the file . It only opens about halfway and
then stops loading .
[Edited on 1-5-2007 by Rosco Bodine]
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Axt
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Attached: "Some aromatic nitrate esters: synthesis, structural aspects, thermal and explosive properties" Journal of Hazardous Materials A77 2000
11–31
Attachment: Some aromatic nitrate esters- synthesis, structural aspects, thermal and explosive properties.pdf (422kB)
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Axt
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Attached: "Tetryl, Pentyl, Hexyl, and Nonyl: Preparation and Explosive Properties" Journal of Chemical and Engineering Data, Vol. 8, No. 1, pg.
135-150, January 1963.
Attachment: tetryl-pentryl-hexyl-nonyl preperation and explosive properties.pdf (1.5MB)
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Axt
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Just another thought before I forget, glucosamine -CH(OH)-O-CH(OH)-CH(OH)-CH(OH)-CH(NH2)- join the ends into ring, is readily and cheaply available as
its sulphate from health food suppliers. Assuming no steric reasons prevent the analogy between this and pentryl it would be a very nice energetic
C<sub>11</sub>H<sub>7</sub>N<sub>9</sub>O<sub>21</sub>.
Add glucosamine sulphate to NaOH/EtOH, filter sodium sulphate then try to condense with DNCB.
And while I'm here, the attached article would be interesting if it were not in chinese
[Edited on 29-5-2007 by Axt]
Attachment: study of the etherification of 2,4-dinitrochlorobenzene.pdf (214kB)
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franklyn
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3,5-DichloroTrinitroanisole to TATB
Funny where things will lead sometimes , while researching Trinitroanisole ( Methoxy Picrate )
http://www.onlinechemical.net/redirect.php?fid=13&tid=10...
http://www.roguesci.org/megalomania/explo/trinitroanisol.htm...
a relatively insensitive secondary explosive according to _ http://cameochemicals.noaa.gov/chemical/12888
it being an ether and listed as subject to forming a peroxide at the number one
methoxy group position , a compound apparently uninvestigated , it would thus
have primary explosive characteristic analogous to other picrate derivatives .
Methoxy picrate cannot be readily made by reacting picric acid with methanol. However
the Methyl Phenolate which is a Phenol Methyl ether, Methoxybenzene , ( synthesis
reference here _ http://www.pherobase.net/database/synthesis/synthesis-detail... )
can itself be readily nitrated in good yield although dangerously.
See page 169 C.O.P.A.E , Davis
and > http://www.pnas.org/cgi/reprint/75/2/545.pdf
also > http://en.wikipedia.org/wiki/Anisole
Refluxing Methoxy Picrate with ammonia yields Picramide ( Trinitroaniline ) See below why this matters. **
Any way the point is I happened upon these two patent citations :
Preparation of 1,3,5-triamino-2,4,6-trinitrobenzene from 3,5-dichloranisole
United States Patents 4952733 , 4997987
Describe the preparation of TATB by nitration of 3,5-dichloroanisole to
produce 3,5-dichlor-2,4,6-trinitroanisole which is further chlorinated to
give 1,3,5-trichloro-trinitrobezene which is ammonolyzed to yeild TATB.
**It appears this last chlorination could be left out to yield the product
directly. If this has merit , then the better explosive TATB is as easily
prepared as Trinitroaniline from a related precursor.
3,5-Dichloranisole ( 3,5-Dichloro-1-Methoxy Benzene )
http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=2486...
A related reference is
Preparation of 1,3,5-Triamino-2,4,6-Trinitrobenzene from 3,5-Dichloroanisole
D.G. Ott and T.M. Benziger / Journal of Energetic Materials - 1987 ,
Vol 5/3-4 , pages 343 - 354
For reference , the prior art and method is detailed here _
http://www.roguesci.org/megalomania/explo/trichlorotrinitrob...
http://www.roguesci.org/megalomania/explo/TATB.html
http://www.llnl.gov/str/Pagoria.html
I also came upon this patent citation for Nitrobenzofuroxans derived much
the same way as TATB above , are not secondary explosives but exhibit
desirable properties as substitutes for existing primary explosives.
Nitrobenzodifuroxan compounds, including their salts, and methods thereof
United States Patent 7145016
A related reference is
http://pdf.aiaa.org/preview/CDReadyMJPC2005_1177/PV2005_3512...
.
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Axt
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| Quote: | Originally posted by franklyn
it being an ether and listed as subject to forming a peroxide at the number one methoxy group position , a compound apparently uninvestigated...
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Theres no mention of it forming peroxides in the page you liked to. There is a peroxide derivative of picryl chloride (and possibly DNCB), with the
peroxide group being introduced via reaction with sodium peroxide in the same way other peroxides are derived from acid chlorides. The only mention of
this I have seen is on pg 330 of "High Explosives" by Colver (1918), which I've attached. I'd disregard the synthesis info, as I doubt picryl chloride
is soluble to that extent, at least not without reacting to form picric acid and neither are stable in heated solution. I couldn't find the patent
which is being refered to, even though there is a large review of patents at the back of that book. Reacting a cold aqueous solution of Na2O2 with a
fine dispersion of TNCB would make more sense, or possibly a 2 phase solvent system. Also, its not mentioned but using a 2:1 molar ration Na2O2 to
TNCB could well result in bis(trinitrophenyl) peroxide.
| Quote: | | Methoxy picrate cannot be readily made by reacting picric acid with methanol. |
No, but it can with DNCB, the synthesis is in the chinese article above. This is the easiest route as the mononitration of dinitroanisole is far
easier then the trinitration of either anisole or chlorobenzene.
| Quote: | | Describe the preparation of TATB by nitration of 3,5-dichloroanisole to produce 3,5-dichlor-2,4,6-trinitroanisole which is further chlorinated to give
1,3,5-trichloro-trinitrobezene |
3,5-dichloroanisole doesnt look like a particularly convenient precursor, trinitrotrichlorobenzene still looks easiest through the most published
route, that being by chlorinating aniline, diazotisation to trichlorobenzene followed by nitration.
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franklyn
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I concluded " it being an ether and listed as subject to forming a peroxide "
in the context of where it is mentioned , but there is no specific mention of
Methyl Picrate ( Trinitrophenylmethyl ether ) forming a peroxide as such.
http://www.hawaii.edu/ehso/hazmat/PEROXIDES.pdf
(I V) Aromatic ethers (8) , and section ( D ) here _
http://www.dncustoms.gov.vn/web_eglish/bieu_thue/E_HTM/E2909...
There are warnings about Anisole
http://info.anu.edu.au/hr/OHS/_Procedure_Attachments/Explosi...
http://ehs.ucsc.edu/lab_research_safety/pubs/facts/Peroxides...
Finding a reference has proven to be elusive. I am aware that methoxides
will form so called Meisenheimer Complexes ( addition compounds ) with
Trinitroanisole.
http://en.wikipedia.org/wiki/Meisenheimer_complex
http://books.google.com/books?id=lNCr3TiF1_0C&pg=PA386&a...
_____________________
I could have done a little more reasearch on TATB , the methods I cited are
discussed here _
The Organic Chemistry of Explosives ( Agrawal and Hodgson )
Page 136 , 4.3.2.6 Halobenzenes
paragraph below figure 4.11 relates to the TATB precursors
Page 172 , 4.8.4 Synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)
paragraph below figure 4.56 specifies obtaining TATB from
3,5-Dichloro-2,4,6-Trinitroanisole
Page 173 at the top outlines my conjecture
As you say , availability of 3,5-Dichloroanisole is problematic , it is expensive
and only made in China I understand.
______________________
Related citation for Picramide ( Trinitroaniline ) from Methyl Picrate ( Trinitroanisole )
http://books.google.com/books?id=GqWHe4eW87gC&pg=PA464&a...
United States Patent 4032377
Describes the 1,3,5-trichloro-trinitrobezene route
to TATB and overcoming shortcomings.
.
[Edited on 15-10-2007 by franklyn]
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Mardec
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Hmm, I can't seem to find any H2NCH3CH3OH.
And if I start from bromobenzene, can I proceed like it is chlorobenzene in the syntheses?
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Axt
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Yes you an use dinitrobromobenzene for the condensation with ethanolamine. If you want reference to the reaction in 95% yield theres Doklady Akademii
Nauk SSSR, 308(5), 1150-4 [Chem.]; 1989
Anyways regarding the peroxidic derivative discused above, this is from Chem. Ber. (1961), 94, 1156-7.
"The prepn. of Na perpicrate from picryl chloride with Na2O2 in aq. soln. according to the directions of Vosswinkel (Ger. 96,855) could not be
duplicated. All attempts to prep. perpicric acid from picryl chloride with H2O2-Et2O, cumene hydroperoxide, the Na deriv. of cumene hydroperoxide, or
Pr3COOH in the presence of C5H5N at 0 were unsuccessful."
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almaz
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After reading about Pentryl I decided to repeat it. With pure benzene and dichloroisocyanuric acid I prepared chlorobenzene. 15 g of benzene and 21 g
of chlorine tablets with 50% sulfuric acid. Then follows it up nitrate DNCB and I came to a standstill. Can I replace the nitration reaction of
potassium nitrate on ammonium nitrate?? Yes, I also have oleum good quality, it can be used in the reaction or whether a 96% sulfuric acid? Do not
ignore questions of friends. Ethanolamine, I received from the means for removing grease from microwaves Top Hourse. I mixed it with ethanol, then
filtered from the precipitate and heated to the boiling point of ethanolamine. The result was a yellowish, viscous liquid which froze in the cold. Do
not ignore questions of friends. Thank you.
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