2,4,6-Trinitroanisole 3,5-Trinitrobenzene

The kinetics and mechanism of Meisenheimer s reaction has been studied by Caldin and Ainscough [43] who utilized the reactions of addition of sodium etho-xylate to trinitroanisole, trinitrobenzene and trinitrotoluene. By using temperatures in the range from -70°C to -100°C they were able to reduce the reaction rate to a measurable value. On treating the addition product with acetic acid at temperatures ranging from -50°C to -80°C they obtained the starting product. Thus, the reaction was proved to be reversible, as for example in the case of trinitroanisole (TNA) ... 

Explosives Store in secure location away from all other chemicals. Ammonium nitrate, nitro urea, picric acid, trinitroaniline, trinitroanisole, trinitrobenzene, trinitrobenzenesulfonic acid Flammable liquids, oxidizers, poisons, acids, and bases... 

It was prepd in 1884 by Nolting and Collin (Ref 2) from ethyl- or methyl-esters of Styphnic Acid and ale ammonia. Blanksma (Ref 3) prepd it from 3-chlor-2,4,6-trinitroanisole (or 3-chlbr-2,4,6-trinit,rophetietole) and ale ammonia, Kbrner and Contardi ( Ref 4) from 2,4-dibrom- (or dichlor)- 3,5-trinitrobenzene and ale ammonia, and Fliirscheim (Ref 5) from tetranitro-aniline and ammonia... 

Trinitrobenzene is present in crude TNT manufactured by mixed acid nitration and results from methyl group oxidation followed by decarboxylation." In fact, a convenient method for the synthesis of 1,3,5-trinitrobenzene involves oxidation of 2,4,6-trinitrotoluene with a solution of sodium dichromate in sulfuric acid, followed by decarboxylation of the resulting 2,4,6-trinitrobenzoic acid in boiling water." 1,3,5-Trinitrobenzene is prepared from 2,4,6-trinitro-m-xylene by a similar route." 2,4,6-Trinitroanisole can be prepared from the... 

Following are some copper compression values in mm as given by Kast (Ref 4, p 184) Blasting gelatin 4.8, Dinitrobenzene 2.9 Guncotton (dry) 3.0, Hexanitrodiphenylamine 4.1, Nitroglycerine 4.6, Picric acid 4.1, Tetryl 4.2, Trinitroanisole 3-5, Trinitroanisole 3-6, Trinitrobenzene 4.1, Trinitrocresol 3-5, and Trinitrotoluene 3.6... 

It is of interest that the equilibrium constant for sulphite addition to 2,4,6-trinitroanisole is similar in this case to the value for 1,3,6-trinitrobenzene, addition occurring in each case at a ring carbon carrying hydrogen. This indicates that the electronic effects of the substituents at Cl do not appear to affect the stabilities of the adducts greatly. The increased stability of the picramide complex may result from some... 

With 1,3,5-trinitrobenzene no diversity of attack is possible, though for substituted derivatives such as 2,4,6-trinitroanisole or 2,4,6-trinitro-aniline the mode of interaction may vary on changing the nucleophile. Thus structural measurements show that the thermodynamically stable adducts of 2,4,6-trinitroanisole with OMe-, Ns- or NEt2 result from addition at Cl while the apparently stable adducts with S03 or CHg CO CH2 are formed at C3. The failure to detect addition of these latter nucleophiles at Cl may be ascribed to steric strain. This may occur either in the Cl adducts themselves, so that they are no longer thermodynamically preferred to the C3 adducts, or alternatively in the transition states for their formation, so that their formation is very slow. Again the mode of ionization of 2,4,6-trinitroaniline and its N-substituted derivatives depends on the relative affinities for carbon or hydrogen of the particular nucleophile used. Thus sulphur bases such as SEt- and SPh will preferentially add at the 3-position, while with oxygen bases abstraction of an amino proton also occurs. 

The covalent adducts such as [3] and [4] which were known to be formed from 2,4,6-trinitroanisole and 1,3,5-trinitrobenzene, respectively, and methoxide ion in methanol (Meisenheimer, 1902) served as models for [I]. It can be noted that conclusive proof of the structure of [3] and [4] was obtained from nmr spectra of the... 

That is the reason why the performance of Picric Acid (trinitrophenol) is only very slightly higher than that of Trinitrobenzene and why the performance of Trinitroanisole is much the same as that of Trinitrotoluene... 

The exclusive formation of the C-1 adduct between 2,4,6-trinitroanisole and n-butylamine has actually been detected, as a transient intermediate en route to AT-(n-butyl)picramide, by a low-temperature flow n.m.r. experiment. Further kinetic data for the reversible reaction between the 1,3,5-tri-nitrobenzene-methoxide cr-complex and aniline in DMSO-MeOH solutions, yielding the 1,3,5-trinitrobenzene-anilide dissociative mechanism involving rate-determining interconversion of free TNB and the protonated anilide complex. The failure of aromatic primary amines by themselves to form stable (7-complexes with TNB is due to an unfavourable overall equilibrium represented by equation (3), while the additional presence of the strong base... 

When picryl chloride is mixed with a solution of sodium methoxide in methanol, a red salt is formed (34). Analyses are consistent with a structure in which chloride has been replaced by methoxide and a molecule of sodium methoxide has been added. An alternate possibility would involve abstraction of a proton from initially formed trinitroanisole to give a salt which retains a molecule of methanol of crystallization. This product may be heated to 130° without loss of weight but is transformed by ethanol into a new salt in which a methyl has been replaced by an ethyl group. The possibility of a proton abstraction from the ring was considered improbable since deBruyn had shown that s-trinitrobenzene in xylene is not acted on by metallic sodium even at the boiling point of the solvent (35). 

These studies by Caldin et al. thus explain, in a completely satisfactory manner, Foster s originally puzzling observation that the interactions of alkoxides with s-trinitrotoluene, s-trinitroanisole, and s-trinitrobenzene result in products having strikingly different visible absorption spectra. In the first case, XII is formed by abstraction of a proton from the methyl group in the second, the process is one of addition to give III in the third, a charge-transfer complex is formed. These are three distinctly different structural types, and it is to be expected that their visible spectra will differ. 

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