Polynitro synthesis

A comprehensive discussion of the synthetic methods used to introduce the nitro group into aliphatic compounds, and its diverse chemistry, would require more space than available in this book. While every effort has been made to achieve this, some of these methods are given only brief discussion because they have not as yet found use for the synthesis of energetic materials, or their use is limited in this respect. The nature of energetic materials means that methods used to introduce polynitro functionality are of prime importance and so these are discussed in detail. Therefore, this work complements the last major review on this subject. ... 

Olah showed that nitrations can be split into the three categories of electrophilic, nucleophilic and free radical nitration. Free radical nitrations are extensively used for the industrial synthesis of low molecular weight nitroalkanes from aliphatic hydrocarbons. Nucleophilic nitration is the basis for a number of important methods for the synthesis of nitro and polynitro alkanes. Generally speaking only electrophilic nitration is of preparative importance for the... 

Nitration via diazotisation has been extensively used for the synthesis of isomeric dinitronaphthalenes. Ward and co-workers used nitration via diazotisation to prepare 3,3, 4,4 -tetranitrobiphenyl from 3,3 -dinitrobenzidine, and 3,4,5-trinitrotoluene from 3,5-dinitro-4-toluidine. Ward and Hardy " prepared 1,4,6-trinitronaphthalene from 4,7-dinitro-1-naphthylamine. Korner and Contardi used the nitrate salts of aryldiazonium compounds for the synthesis of polynitro derivatives of benzene " and toluene. " " Accordingly,... 

Considerable current interest and sustained research efforts of some groups in the USA and other countries have been aimed at the synthesis and chemistry of strained energetic compounds. According to Marchand and co-workers, polynitro polycyclic cage compounds are important members of this class [110]. 

Regarding the 1,3-diazocines, it was reported that the synthesis of the left domain of haplophytine, a hetero-dimeric alkaloid endowed with insecticidal activity, contained a pyrrolo-fused carbonyl bridged 1,3-benzodiazocine moiety <2007AG(E)4715>. It was also reported that the synthesis of a pyrazolo-fused 1,3-benzodiazocine and its activity as inhibitor of lymphocyte-specific protein tyrosine kinase (Lck) <2007W0026720>, and the thermal decomposition of a polynitro substituted 1,3-diazocine <2006RJGC499>. 

Carrol, P.J., Dailey, W.P., and Wade, P.A. 1987. Polynitro-snbstituted strained-ring compounds. Synthesis, mechanism of formation, and structure of tran -dinitrocyclopropanes. Journal of the American Chemical Society, 109(18) 5452-6. 

The addition occurs in the presence of polymerization inhibitors such as copper stearate, aromatic polynitro compounds, or sterically hindered phenols and then sometimes requires days or weeks. In spite of the often tedious procedure the method is of great interest since, from cheap materials, it often affords good yields of compounds containing the phospholene ring system which is otherwise difficultly accessible. Compounds of type (1) and (2) have also considerable interest as efficient catalysts for the carbodiimide synthesis (cf. page 504). 

Hantzsch and Rinkenberger [171] established that TNM can quantitativelv be liydrolysed to trinitromethane by potas.sium hydroxide or potassium et oxide. However, aqueous concentrated KOI I can produce a deeper hydrolysi-with the formation of KNO3, KNOi and K COj [172]. The reaction of thv formation of irinitrornctliune ( nitroform ) from TNM became a stanclar. method of making iiitrolbrm used for synthesis of polynitro aliphatic com pounds. 

G. A. Olah in Chapter 7 reviews some of the most useful methods in preparing nitro compounds (i.e., electrophilic nitrations with superacid systems, nitronium salts, and related Friedel-Crafts type complexes). Polynitro compounds were traditionally and still are the most widely used explosives [e.g., nitroglycerol, trinitrotoluene (TNT), and Af-nitramines (RDX and HMX)]. Methods of preparing nitro compounds thus remain a key part of the synthesis of energetic materials. 

Bell, A.J. and Read, R.W. (1987) Synthesis of polynitro-substi-tuted 2 -nltroblphenyl-2-amines, analogues of polynitro ben-zo[c]clnnollne oxide derivatives, Aust. J. Chem. 40, 1813-1829. 

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