1- -2,4,6-trinitrobenzene

5-Trinitrobenzene may be prepared by heating the sodium salt of 2 4 6-trinitrobenzoio acid with water  

The compound is employed for the characterisation of aromatic hydrocarbons (compare Section IV,9), ethers and amines. 

Benzyl chloride reacts with thiourea in dilute alcoholic solution to give iS benzyl-iso-thiuronium chloride  

The compound separates in either, sometimes as both, of two dimorphic forms, m.p. 150° and 175° respectively. The former may be converted into the higher m.p. form by dissolving It in alcohol and seeding with crystals of the form, m.p. 175° the low m.p. form when warmed to 175° gives, after solidification, a m.p. of 175°. Both dimorphic forms give identical derivatives with carboxylic acids and sulphonic acids (see Sections 111,85 and IV,33). 

Method 1. Dissolve 76 g. of thiourea in 200 ml. of warm water in a 750 ml. or 1 litre round-bottomed flask. Dilute the solution with 135 ml. of rectified spirit and add 126 5 g. of benzyl chloride. Heat the mixture under reflux on a water bath until the benzyl chloride dissolves (about 15 minutes) and for a further 30 minutes taking care that the mixture is well shaken from time to time. Cool the mixture in ice there is a tendency to supersaturation so that it is advisable to stir (or shake) the cold solution vigorously, when the substance crystallises suddenly. Filter off the solid at the pump. Evaporate the filtrate to about half bulk in order to recover a further small quantity of product. Dry the compound upon filter paper in the air. The yield of S-benzyl iso-thiuronium chloride m.p. 174°, is 205 g. Recrystallise the salt from 400 ml. of 0-2N hydrochloric acid filter off the solid which separates on cooling. Concentrate the filtrate to recover a further small quantity. The yield of recrystallised salt, m.p. 175° is 185 g. some of the dimorphic form, m.p. 150°, may also separate. 

Method 2. Place a mixture of 126-5 g. of benzyl chloride, 76 g. of thiourea and loO ml. of rectified spirit in a 500 ml. round-bottomed flask fitted with a reflux condenser. Warm on a water bath. A sudden exothermic reaction soon occurs and aU the thiourea passes into solution. Reflux the resulting yellow solution for 30 minutes and then cool in ice. Filter off the white crystals and dry in the air upon filter paper. Concentrate the filtrate to half its original volume and thus obtain a further small crop of crystals. The yield of crude S-benzyl-wo-thiuronium chloride, m.p. 14o°, is 236 g. ItecrystaUise from 0-2iV hydrochloric acid as in Method 1 the m.p. is raised to 150°, although on some occasions the form, m.p. 175°, separates. 

Other Names 1,3,5-Trinitrobenzene 2,4,6-Trinitrobenzene NSC 36931 TNB TNB (nitro compound) Trinitrobenzene i-Trinitrobenzene sym-Trinitrobenzene CA Index Name Benzene, 1,3,5-trinitro-CAS Registry Number 99-35-4 Merck Index Number 9726 Chemical Structure 

Chemical/Dye Class Nitro Molecular Formula C6H3N3O6 Molecular Weight 213.10 pH Range 11.5-14.0 

Solubility Slightly soluble in water soluble in ethanol 

Applications Explosive,high-energy propellants,energetic materials,display device, electroluminescent materials, lithium batteries, paints, adhesives  

Safety/Toxicity Cytotoxicity, carcinogenicity,22 chronic toxicity,25 environmental toxicity,2 genotoxicity,25 hazardous substance,2 hematological effects,22 immunotoxicity,2 marine toxicity, 2 mutagenicity,5o neurotoxicity, phytotoxicity, soil toxicity, testicular effects  

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Unlike aliphatic hydrocarbons, aromatic hydrocarbons can be sul-phonated and nitrated they also form characteristic molecular compounds with picric acid, styphnic acid and 1 3 5-trinitrobenzene. Many of the reactions of aromatic hydrocarbons will be evident from the following discussion of crystalline derivatives suitable for their characterisation. 

Dissolve equimolecular quantities of the hydrocarbon and 1 3 5 trinitrobenzene in hot alcohol, benzene or glacial acetic acid, and allow to cool. Filter oflf the solid which separates and recrystallise it from one of these solvents. 

Trinitrobenzene, 1,3,5-trinitrobenzene (indicator) dissolve 0.1 g in 100 mL alcohol pH range colorless 11.5-14.0 orange. 

Aromatic hydrocarbons can be purified as their picrates using the procedures described for amines. Instead of picric acid, 1,3,5-trinitrobenzene or 2,4,7-trinitrofluorenone can also be used. In all these cases, following recrystallisation, the hydrocarbon can be isolated either as described for amines or by passing a solution of the adduct through an activated alumina column and eluting with toluene or petroleum ether. The picric acid and nitro compounds are more strongly adsorbed on the column. 

Benzo[ghi]perylene (1,12-benzoperylene) [191-24-2] M 276,3, m 273°, 277-278.5°, 278-280°, Purified as light green crystals by recrystn from CfiH6 or xylene and sublimes at 320-340° and 0.05mm [UV Helv Chim Acta 42 2315 7959 Chem Ber 65 846 1932 Fluoresc. Spectrum J Chem Soc 3875 7954]. 1,3,5-Trinitrobenzene complex m 310-313° (deep red crystals from C6Hg) picrate m 267-270° (dark red crystals from CgH6) styphnate (2,4,6-trinitroresorcinol complex) m 234° (wine red crystals from CgH6). It recrystallises from propan-l-ol [J Chem Soc 466 7959]. 

Benzo[e]pyrene (1,2-benzpyrene) [192-97-2] M 252.3, m 178-179 , 178-180 . Purified by passage through an AI2O3 column (Woelm, basic, activity I) and eluted with CgHg and recrystd from 2 volumes of EtOH- CeHe (4 1). Forms colourless or light yellow prisms or needles. [J Chem Soc 3659 1954 Justus Liebigs Ann Chem 705 190 1967.] 1,3,5-Trinitrobenzene complex m 253-254° (orange needles from... 

Trinitrobenzene reacts with dry acetone in the presence of potassium methoxide to give a crystalline violet compound CgHsN OjK. Deduce its identity from the C NMR spectra 18. Conditions ( 03)280, 25 °C, 22.63 MHz. (a) //broadband decoupled spectrum (b) without decoupling (c) expanded section of (b). 

A novel indole ring formation involving DBU nucleophilic addition to 1,3,5-trinitrobenzene has appeared as shovm in Eq. 10.69. 

Speculate as to whether the combustion of 1,3,5-trinitrobenzene, C6H3(NO,)3, or the combustion of 1,3,5-triaminobenzene, CftH3(NH2)3, would be more exothermic. Support your answer with appropriate calculations. 

The composition and nature of the charge-transfer complexes of 2-quinoxalina-mine with tetrachlorobenzoquinone (chloranil), tetrabromobenzoquinone (bromanil), 1,3,5-trinitrobenzen, and picric acid have been determined likewise those of 2,3-quinoxalinediamine with chloranil and bromanil. 

Complexes in Which the Acceptor Is an Organic Molecule. Picric acid, 1,3,5-trinitrobenzene, and similar polynitro compounds are the most important of these. Picric acid forms addition compounds with many aromatic hydro... 

Such cyclohexadienes are easily oxidizable to benzenes (often by atmospheric oxygen), so this reaction becomes a method of alkylating and arylating suitably substituted (usually hindered) aryl ketones. A similar reaction has been reported for aromatic nitro compounds where 1,3,5-trinitrobenzene reacts with excess methyl-magnesium halide to give 2,4,6-trinitro-l,3,5-trimethylcyclohexane. Both... 

OS 31] ]R 4] ]P 23] Under electroosmotic flow conditions, the reactant benzene was mobilized as a microemulsion using sodium dodecyl sulfate (SDS) as surfactant [103] (see also [14]). The nitronium ions, generated in situ from sulfuric and nitric acid, were moved by electrophoretic forces. By this means, a 65% yield of a nitrobenzene was obtained consecutive nitration products such as 1,3-dinitrobenzene (8% yield) and 1,3,5-trinitrobenzene (5% yield) were also produced. 

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