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Sauron
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So the yield is trivial and the purification problematic. Oh joy.
These problems do not apply to the James procedure for chlorination of MeSCN. High yield, and the cyanuric chloride crystallizes out of the mixture
and is simply filtered off and recrystallized. My recollection is that from 100 g MeSCN 65-70 TCT are obtained. When the chlorination no longer throws
TCT, continue chlorination till onloy CCl4 and sulfur chlorides remain, then work that up in usual way (see my recent post on CCl4 from CS2) to obtain
max. CCl4.
So use the KSCN to prepare MeSCN (I also posted this before.)
Kn the interest of finding a practical prep of TCT that does not involve such toxic reagents or intermediates, let's reexamine the chlorination of CA
(NC-OH)3 + 3 PCl5 -> 3 POCl3 + 3 HCl + (CNCl)3
129 g 615 g 453 g 108 g 183 g
Just as in the case of oxalic acid it seems a great way to make POCl3 and a middling way to make trhe TCT.
However, the situation is just as bad with SbCl5. The difference is the latter is more available. If it works, which seems likely.
Here is the James paper from J.Che.Soc.
Remember TCT is the first product formed, and is solid and insoluble so ppts out.
You do not need to be concerned with the details of the rest of the intermediates, just continue chloribating after no more TCT drops out, and you
will eventually have only CCl4 and sulfur chlorides. James gives the overall stoichiomeyrt.
3 CH3SCN + 11 Cl2 -> Cl3(CN)3 + 2 CSCl4 + CSCl2 + 9 HCl
but a further mol Cl2 converts the thiophosgene to CSCl4
CSCl2 + Cl2 -> CSCl4
and 3 more mols Cl2 convert the three mols of trichloromethyl sulfenyl chloride to CCl4 and SCl2
3 CSCl4 + 3 Cl2 -> 3 CCl4 + 3 SCl2
So that the overall reaction for the perchlorination is
3 CH3SCN + 15 Cl2 -> Cl3(CN)3 + 3 CCl4 + 3 SCl2 + 9 HCl
Treating the CCl4/SCl2 mixture with CS2 gets more CCl4 and precipitates elemental sulfur. See my posts on prep of CCl4.
Attachment: jamesMeSCN.pdf (329kB)
This file has been downloaded 814 times
Sic gorgeamus a los subjectatus nunc.
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Engager
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I'm finaly obtained some cyanuric chloride, to make some cyanuric triazide. What is sensitivity of cyanuric triazide? Is it safe to handle it in
common manner (e.g. use vacuum filtering)? What exactly is sensitivity of this compound, especialy sensitivity to friction? Books state that compound
may be excessively sensitive to friction, and can explode from slightest stimulus then crystalls are large. How to ensure to precipitate very fine
crystalls and to handle it safely?
[Edited on 3-7-2009 by Engager]
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The_Davster
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Engager: Sensitivities of it were mentioned in this PDF. (http://www.dtic.mil/ndia/2006fuze/mehta.pdf)
It seems to be around lead azide, nice to see that it is of lower ESD sensitivity though.
I have also heard some bad things about its sensitivity in the molten state, namely, very high.
[Edited on 4-7-09 by The_Davster]
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Engager
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Document shows general sensitivity, but does not describe conditions of production or crystall size of cyanuric triazide, but sensitivity clearly very
dependent from it. "Large" crystalls said to explode on touch and friction by rubber rod. Such sensitivity is absolutely unacceptable, what's why i'm
looking for method to produce small crystalls, witch can be handled in relatively safe manner. Does someone have any idea what is reference from witch
prep posted by pdb was taken? Where i can get safe synth procedure for CTA in form of very small crystalls, witch are much less sensitive?
[Edited on 4-7-2009 by Engager]
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PHILOU Zrealone
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Engager,
Here some info on friction..
Out of Explosives (Josef Köhler and Rudolf Meyer, 4th revised and extended edition):
p 70:
"Cyanuric triazide:
(-N=C(N3)-)3
colorless crystals
empirical formula: C3N12
molecular weight: 204,1
energy of formation: +1088 kcal/kg = + 4551 kJ/kg
enthalpy of formation: + 1071 kcal/kg = + 4481 kJ/kg
oxygen balance: -47%
nitrogen content: 82,36% N
melting point (under decomposition): 94°C = 201°F
lead block test: 415 cm³/10g
detonation velocity unconfined: 5500 m/s (at d= 1,02 g/cm³) (*)
deflagration point (explosion): 200-205°C = 390-400°F
friction sensitivity: 0,01 kp = 0,1 N pistil load "(**)
(*)Note that the density can be higher and that 5500 m/s is listed as unconfined, what would imply that the VOD can be very much higher, because VOD
is density and confinement dependant
(**) pistil load charged with roughly 10 grams!!! thus very friction sensitive
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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