99-35-4

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(Figure Presented) Electrochemical reduction of 1,3,5-trinitrobenzene (1) forms π dimer 2, which evolves to a more stable ω complex. The crystal structure of the NEt4+ salt of 2 shows π-stacked chains of radical anions. Solid 2 or dimeric 2 in solution reacts with N2 to give a dianion in which an azo group links two 1,3,5-trinitrobenzene units (see picture). The azo derivative is reversibly electrochemically oxidized to 1.

Reductive desulphonation of 2,4,6-trinitrobenzenesulphonate by N-dodecyl-1-benzyl-1,4-dihydronicotinamide bound to the sodium dodecyl sulphate micelle in D2O solution gave 1,3,5-trinitrobenzene which contained 4.6-5.1percent of deuterium; the result indicates that the reaction proceeds through multi-step hydrogen transfer via a radical ion-pair intermediate and the micelle surface is capable of dissociating the radical ion pair.

1,8-Naphthalenedisulfonate was reductively desulfonated by N-benzyl-1,4-dihydronicotinamide, whereas no desulfonation was observed for the 1,6-isomer.The high reactivity of the 1,8-isomer is attributed to the steric-strain that enforces the shift of the initial state with the sp2-carbon close to the transition state with the sp3-carbon.

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A procedure was developed for preparing a new trifunctional vulcanizing agent for unsaturated rubber composites, 1,3,5-trinitrosobenzene; its suitability as an additive to rubber-substrate adhesive formulations was examined.

The invention relates to a method for preparing 1, 3, 5-trinitrobenzene, and belongs to the technical field of organic intermediates. The method comprises the following steps: respectively preparing a TNT alcoholic solution and a sodium chlorite aqueous solution, adjusting the pH value of the TNT alcoholic solution with hydrochloric acid, heating to a reaction temperature, dropwise adding the sodium chlorite aqueous solution into the TNT alcoholic solution, reacting at a constant temperature, and finally filtering, washing and recrystallizing to obtain the 1, 3, 5-trinitrobenzene. Sodium chlorite is adopted as an oxidizing agent, so that oxidation and decarboxylation reactions are completed in one step, the process is simplified, and the operation cost is reduced; the energy consumption required by the reaction is low, and the product purity is high; the reaction process is safer, and the reaction yield is higher.

The invention discloses a synthesizing method of 2, 6 diamido-4-carboxyl benzenesulfonic acid, which belongs to the technical field of chemical synthesis. 2,6 diamido-4-carboxyl benzenesulfonic acid is prepared by taking benzene as a raw material, adding reaction liquid mixed by concentrated nitric acid and concentrated sulfuric acid, mixing, washing with a sodium hydroxide solution, reacting with stannous chloride, iron powder and acetic acid, dropwise adding nitric acid and mixing to obtain triaminobenzene, adding sulphurous acid, under the action of sodium percarbonate, dropwise adding the sodium hydroxide solution for reaction, adding concentrated sulfuric acid after suction filtration, accelerating the reaction under the catalyst tetrabromoethane, adding hydrochloric acid for reaction, washing, performing suction filtration and cooling to room temperature. The synthesizing method has the beneficial effects of simple synthesizing steps, low cost, less side products in the preparing process, and high purity (more than 99.2%) and high yield (more than 95%) of the obtained 2,6 diamido-4-carboxyl benzenesulfonic acid.

Various thermally stable energetic polynitro-aryl-1,2,3-triazoles have been synthesized through Cu-catalyzed [3+2] cycloaddition reactions between their corresponding azides and alkynes, followed by nitration. These compounds were characterized by analyti

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Advantages of the electrochemical approach in the nucleophilic aromatic substitution reaction, such as (a) low cost and ready availability of reagents, (b) atom economy, and (c) high yields (approaching 100 %), are applied to rationalize the (polar or radical) mechanism and to develop new greener synthetic routes for the synthesis of substituted nitroaromatic organophosphorus compounds. The nucleophiles used to study the feasibility and viability of the reaction are the classical tervalent phosphorus nucleophiles: trimethylphosphane, triethylphosphane, triphenylphosphane, diphenylphosphane, trimethyl phosphite, triethyl phosphite, dimethyl phosphonate, diethyl phosphonate, oxo(diphenyl)phosphorane, with two nitroaromatic compounds 1,3,5-trinitrobenzene and 1-chloro-2,4,6-trinitrobenzene in a DMF solution containing 0.1 M tetrabutylammonium tetrafluoroborate. In all cases, in order to establish the feasibility or benefits of the electrochemical approach relative to the chemical approach, blank reactions were also performed. Electrochemical oxidation of σH complexes and zwitterionic complexes obtained by nucleophilic attack of phosphorus nucleophiles was studied by means of cyclic voltammetry and controlled-potential electrolysis. The oxidation mechanism of those intermediates was disclosed, and the synthetic scope of the reaction was explored. Copyright

Kinetic and equilibrium studies are reported of the reactions of 1,3,5-trinitrobenzene (TNB) with a series of o-substituted anilines in dimethyl sulfoxide (DMSO) in the presence of 1,4-diazabicyclo[2.2.2.]octane (DABCO). The pKa values in DMSO for the aniline derivatives were measured using the proton-transfer equilibrium with 2,4-dinitrophenol. Kinetic studies are compatible with a two-step process involving initial nucleophilic attack on TNB by amine to give a zwitterionic intermediate which may transfer an acidic proton to DABCO to yield the anionic product. The results indicate steric hindrance to proton transfer in reactions involving 2,6-disubstituted anilines.

An environmentally friendly picric acid explosive comprising, providing a nitromalondialdehyde, providing a dinitroketone, reacting the nitromalondialdehydes with the dinitroketone to produce a mixture, and subjecting the mixture to a cyclodehydrative mechanism to produce environmentally friendly picric acid explosive. Embodiments of the present invention include the picric acid explosive produced by the methods of described above.

An environmentally friendly methods for making 2,4-dinitrophenyl compound comprising, providing a nitromalondialdehyde, providing a nitroacetone, reacting the nitromalondialdehydes with the nitroacetone to produce a mixture, and subjecting the mixture to a cyclodehydrative mechanism to produce environmentally friendly 2,4-dinitrophenyl compound. Embodiments of the present invention include the 2,4-dinitrophenyl compound produced by the methods of described above.

Synthesis of 1,3,5-trinitrobenzene was achieved by converting phloroglucinol into its trioximes by reaction with aqueous hydroxylamine followed by oxidation of the trioxime product with 90% nitric acid.

The selective oxidation and halogenation of nitroaromatics is a difficult task both chemically and enzymatically. We have discovered that vanadium chloro- and bromoperoxidases from Curvularia inaequalis and Corralina officinalis, respectively, are capable of catalyzing the hydroxylation, halogenation, and demethylation of 2,4,6-trinitrotoluene (TNT) under alkaline conditions. At pH 8, the conversions for hydroxylation and demethylation reached 38 and 45%, respectively, while direct halogenation was minimal. Vanadium chloroperoxidase generated trinitrobenzyl alcohol with initial rates of 0.27 μM/h-unit enzyme as compared with 0.11 μM/ h-unit enzyme for the vanadium bromoperoxidase. The products of the enzymatic reaction were easily separated and purified and the unreacted substrate recovered. In the presence of PCI5, the trinitrobenzyl alcohol produced by vanadium chloroperoxidase was readily converted to trinitrobenzyl chloride (TNBCI). This chemoenzymatic synthesis may be useful in the environmentally benign synthesis of hexanitrostilbene, a key component of heat-resistant explosive materials.

The reactions among halonitrobenzenes or polynitrobenzenes and alkoxides, thiolates or tertiary amines have provided the evidence that in a SNAr reaction type a single electron transfer from the nucleophile to the aromatic substrate, to generate two radical species within the solvent cage, can take place to some extent. The detection of radical intermediates by EPR spectroscopy, in several SNAr reactions, is reported.

A convenient diastereoselective synthetic route to the molecular tweezer bis(indolizino[3,4-b]quinolyl)methane 9 and the rigid indolizino[7′,8′:2,3]quinolino[8,7-h]indolizino[8,7-b]quinolines 14, 15 as potential receptor molecules has been developed, involving double imine condensation followed by Lewis acid catalyzed biscyclization of prolinal-derived bis-(imines) 8 and 13, respectively. Whereas the use of SnCl4 leads to the formation of the planar polycycle 15, the corresponding concave product 14 is formed in the presence of EtAlCl2. Both compounds 14, 15, as well as tweezer 9 have been characterized by X-ray crystal-structure analysis. Although tris(imines) 20, 24 derived from 1,3,5-triaminobenzene (18) and tris(4-aminophenyl)amine (23) could be obtained similarly by molecular sieve-catalyzed condensation, the corresponding triscyclization could not be achieved. However, by attaching preformed indolizino[3,4-b]quinoline subunits 25 and 31 to an aromatic core, the bidentate receptors 30, 33 and the tentacle molecule 28 were accessible.

Rate and equilibrium constants are reported for reactions in acetonitrile of butylamine, pyrrolidine and piperidine with 1,3,5-trinitrobenzene, 1, and with ethyl 2,4,6-trinitrophenyl ether, 4a, and phenyl 2,4,6-trinitrophenyl ether, 4b. Rapid nucleophilic attack at unsubstituted ring-positions may yield anionic σ-adducts via zwitterionic intermediates, while slower attack at the 1-position of 4a and 4b may lead to substitution to give 2,4,6-trinitroaniline derivatives. Base catalysis in the substitution reaction reflects rate-limiting proton transfer which may be from the zwitterionic intermediates to amine in the case of 4b, or from a substituted ammonium ion to the ethoxy leaving group in the case of 4a. Comparisons with values in DMSO indicate that values of overall equilibrium constants for adduct formation are ca. 104 lower in acetonitrile, while rate constants for proton transfer are ca. 104 higher. These differences may reflect strong hydrogen-bonding between DMSO and -NH+ protons in ammonium ions and in zwitterions. In acetonitrile homoconjugation of substituted ammonium ions with free amine is an important factor.

Decomposition of the N- and C-adducts of indolide anions with 1,3,5-trinitrobenzene is subject to specific acid-catalysis in the former case and general-acid-catalysis in the latter through an SEAr process.

A non-isothermal (NIT) method for evaluating the activation enthalpies and entropies of reactions in solutions was applied to several reversible reactions. This was realized by a stepwise elevation of the temperature of a reaction system using a variable-temperature apparatus comprising on NMR spectrometer and a quick collection of FID (free induction decay) at every plateau of the step. The rate from NIT experiments agreed well with the previously measured rates by the conventional methods.

The thermal stabilities of a number of nitroarenes were examined in solution and in condensed phase.In general, increasing the number of nitro groups decreased thermal stability.Changing the substituent on 1-X-2,4,6-trinitrobenzene from X = H to NH2 to CH3 to OH accelerated decomposition; this effect was attributed to increased ease of intramolecular proton transfer to an ortho nitro group, thus weakening the carbon-nitrogen bond.In solution, the effect of increasing substitution from n = 1 to n = 3 on Xn(NO2)3C6H3-n was uniformly that of decreasing the thermal stability of the species.However, in condensed phase, results suggested that crystal habit may be more important than molecular structure; for X = Br, CH3, and NH2, the more substituted species was the more stable.

Rate and equilibrium measurements are reported for the reactions in methanol of carbanions derived from 12 ring-substituted benzyl cyanides with 1,3,5-trinitrobenzene to give ?-adducts.Some data for reaction of the carbanions with 4-nitrobenzofuroxan were also measured.With increasing carbanion reactivity, rate constants approach a limit of just below 109 dm3 mol-1 s-1.Intrinsic reactivities of carbanions in ?-adduct forming reactions and in proton transfer reactions are compared.

The charge transfer (CT) compexes formed between pyrene with some Dinitrobenzenes (DNB) and 1,3,5-Trinitrobenzene (TNB) acceptors are studied in solution and solid state using UV-visible, infrared and fluorescence spectroscopies.The equilibrium constants (Kc) for these complexes in solution have been calculated.The values of Kc follow the order o-DNB > m-DNB p-DNB TNB.This order is explained by considering the role that steric effects may play in the CT complex formation.In addition, the fluorescence quenching of pyrene with different acceptors is investigated.The effect of medium viscosity and temperature on the efficiency of quenching is also studied.Finally, the electrical properties for the solid CT complexes are measured. - Keywords: Pyrene CT complexes / Equilibrium constants / Fluorescence quenching / Electrical conductivity

Photolysis of benzene/tetranitromethane in dichloromethane or acetonitrile with light of λ>435 nm gives four main product categories, namely, in dichloromethane at +20 deg C (relative yield, products): adducts 1 of hydroxy/trinitromethyl type (total 54percent, see below), nitro substitution products (total 8percent, nitrobenzene, 1,3-dinitrobenzene and 1,3,5-trinitrobenzene), trinitromethyl substitution products (26percent, trinitromethylbenzene, 1-nitro-4-trinitromethylbenzene, 1,3-dinitro-5-trinitromethylbenzene) and phenols (total 12percent, 2,4- and 2,6-dinitrophenol, 2,4,6-trinitrophenol). In acetonitrile at +20 deg C the same product groups comprised 15, 24, 39 and 18percent, respectively, and, in addition, a low yield (1.7percent) of what is formally a cycloaddition product between 4-nitrobenzonitrile N-oxide and acetonitrile, 5-methyl-3-(4-nitrophenyl)-1,2,4-oxadiazole 2. The structure of 2 was determined by single crystal X-ray analysis. The main adducts were assigned the structures of a cis/trans pair of 1-hydroxy-4-trinitromethylcyclohexa-2,5-diene (NMR). Their formation in both dichloromethane and acetonitrile shows that adduct formation from photolysis of tetranitromethane/aromatics is not only confined to polycyclic aromatics but can occur with a maximally resonance-stabilized system, like benzene itself. The high complexity of the product mixture can be explained partly by elimination reactions of adducts, combined with further thermal and photochemical transformations.

Kinetic and equilibrium data for the formation of the adduct from 1,3,5-trinitrobenzene (TNB) with cryptands (221, 222, 21, 22 and di-(Ph-CH2)22) in acetonitrile are reported.The influence of structure and pKa of cryptands on the rate constants, activation and reaction parameters are discussed.A reaction mechanism between TNB and different cryptands has been proposed.

Kinetic and equlibrium data are reported for reaction of hydroxide ions in 20/80 DMSO/water (v/v) with a series of 4'-substituted phenyl 2,4,6-trinitrophenyl sulfides, 1, and with ethyl thiopicrate, 2, ethyl picrate, 3, phenyl picrate, 4, and 1,3,5-trinitrobenzene, 5.In each case a rapid reaction is observed involving reversible hydroxide addition at an unsubstituted ring-position.In the case of 1-4 this is followed by slower, irreversible attack at the 1-position leading to the formation of picric acid.The Hammett ρ value for equilibrium addition of hydroxide to the 3-position of 1 is 0.98, and the ρ value for rate constants for attack at the 1-position is 0.62.The results are discussed in terms of the electronic and steric effects of the 1-substituents.Comparison of 1-5 indicates that changing from an OR to SR group introduces additional steric crowding.However for the reactions studied changing from R = Et to R = Ph has little steric consequence.

The formation of anionic ? complexes between 1,3-dinitrobenzene or 1,3,5-trinitrobenzene and tetrabutylammonium borohydride has been investigated by kinetic measurements. The rate of formation and the stability of the considered complexes are reported and discussed. Kinetic results are explained by the presence of interactions with mainly involve the nucleophile and the solvent.

Kinetic and equilibrium data are reported for the formation of 1:1- adduct from 1,3,5-trinitrobenzene (TNB) with acetate ion derived from potassium acetate and 18C6 crown ether (1:1) in aprotic solvents acetonitrile, tetrahydrofurane, isopropyl ether and toluene.The influence of solvents on the rate constants, activation and reaction parameters are discussed.

Anionic ?-complexes and related structures react with cesium fluoroxysulfate to give predominantly the C-fluoro derivatives: fluoronitrocyclohexadienes or substituted fluoronitrobenzenes.Oxidation or degradation of a complex to form substituted nitrobenzenes is also possible.The balance between all these processes is determined by the structure of the original complex.

Ultrasonic irradiation was found to promote the Ullman coupling of picryl bromide at or below room temperature. In the presence of excess copper, a long-lived intermediate is formed that is quenched upon work-up affording variable mixtures of trinitrobenzene and picric acid.

Kinetic and equilibrium data are reported for nucleophilic attack in methanol at unsubstituted ringpositions of 1,3,5-trinitrobenzene, 2,4,6-trinitrotoluene and 1-chloro-2,4,6-trinitrobenzene by carbanions derived from dimethyl malonate, ethyl cyanoacetate and 4-nitro-, 4-cyano- and 2-cyanobenzyl cyanides.The results are used to determine intrinsic reactivities for the carbanions in these ?-adduct forming reactions and are discussed in terms of the electronic and solvent reorganisation occurring during reaction.

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Dimethyldioxirane oxidizes primary amines rapidly, and generally in high yield, to the corresponding nitro compounds.The method can also be used to syntesize polynitro compounds.

Solutions of sulphuric acid or oleum containing HCl or Cl2 and nitric acid have been found both to chlorinate and nitrate deactivated aromatic compounds.The kinetics and products of the chlorination of 1,3-dinitrobenzene and 1-chloro-2,4-dinitrobenzene in sulphuric acid or oleum containing HCl and nitric acid at 130 deg C, and the kinetics and products of the chlorination of 2,4-dinitrotoluene at 90 deg C in sulphuric acid or oleum containing Cl2 and nitric acid, are reported. 1,3-Dinitrobenzene and 1-chloro-2,4-dinitrobenzene were predominantly chlorinated. 2,4-Dinitrotoluene gave approximately equal amounts of 6-chloro-2,4-dinitrotoluene and 2,4,6-trinitrotoluene.The results show that under these conditions, chlorination and nitration are competing electrophilic reactions, and that chlorination is less selective than nitration.Possible mechanisms for chlorination are discussed.

Yields of the expected nitro products from 1-chloro-4-nitrobenzene and 1,3-dichloro-2-nitrobenzene nitrated at 25 deg C in sulphuric acid or oleum containing 1 mol dm-3 nitric acid were quantitative.The rate profile for nitration of 1,3-dichloro-2-nitrobenzene is normal, but sulphonation is a competing process when the concentration of nitric acid is low.Kinetics of nitration of 1,3-dinitrobenzene at 150 deg C are reported; yields of 1,3,5-trinitrobenzene, the only detected aromatic product, are low.The title chlorodinitrobenzenes each give, on nitration at 130 deg C, a dichlorodinitrobenzene as well as a chlorotrinitrobenzene.The kinetics and yields of the two products from 1-chloro-2,4-dinitrobenzene under a variety of conditions are reported and discussed in relation to a previously proposed mechanism.

2',3,4',5- and 2',3,5,6'-Tetranitrobiphenyl-2-amines, and 2',3,4',5,6'- and 2',4,4',6,6'-pentanitrobiphenyl-2-amines, have been synthesized for the first time, along with the known 2,4,8- and 2,4,10-trinitrobenzocinnoline 6-oxides and 1,3,7,9-tetranitrobenzocinnoline 5-oxide.The benzocinnoline oxide derivatives were found to have higher densities and thermal stability than those of the corresponding biphenylamines.These observations are discussed in terms of structure.

?-Complex formation between 1,3,5-trinitrobenzene (TNB) and N-methylaniline (NMA) in the presence of 1,4-diazabicyclooctane (DABCO) has been studied in dimethyl sulfoxide (Me2SO) solution.The reaction is catalyzed solely by DABCO in a linear fashion, indicating that deprotonation of the zwitterionic intermediate (PH) formed along the reaction coordinate is rate-limiting.Rate and equilibrium constants for the constituents steps have been evaluated.The rate constant for reversion of PH to reactants, k-1, is substantially higher for aromatic amines than for aliphatic amines of comparable basicity.It is suggested that this is a result of stabilization of the transition state for the reactions of aromatic amines through charge delocalization.With NMA as the nucleophile, k-1 is an order of magnitude higher than in the case of aniline, reflecting the effect of release of steric compression in PH on reversion to reactants in the former case.The effect of addition of tetraethylammonium chloride on rates and equilibria in the title reaction was also determined.The overall equilibrium constant for the reaction, K, increases ca. 13-fold as the Et4NCl concentration is increased from 0.03 to 0.30 M.This effect is shown to arise mainly from a decrease in the reverse second order rate constant, kr2.Evidence is presented for the effect of heteroconjugation of the type DABCOH+ + Cl- DABCOH+...Cl- in the processes.The observation of rate-limiting proton transfer in ?-complex formation in this and other systems strengthens the idea that proton transfer can be rate-limiting in nucleophilic aromatic substitution (SNAr) reactions.The present work sheds further light on the apparent dichotomy regarding the differing reactivities of aromatic vs. aliphatic amines as nucleophiles in ?-complex formation.Our results also provide a rationale for the observation that under certain conditions for SNAr reaction involving aromatic and aliphatic amines of the same basicity, the reactions involving the aromatic amine is base catalyzed, while the aliphatic one is not

Hexachloroacetone (HCA) decomposes in dimethyl sulphoxide solution at room temperature.In the presence of an excess of 1,3,5-trinitrobenzene (TNB) the progress of the reaction can be monitored by the appearence of the visible absorption characteristic of the formation of the trichloromethyl Meisenheimer adduct of TNB in nearly quantitative yield (2 mol of adduct per mol of HCA).The reaction is slower than the decomposition of trichloroacetic acid under the same conditions, the difference being attributable to a large negative entropy of activation.The reaction rate is markedly increased by the addition of water and slightly depressed by addition of acid.The kinetics are consistent with a rate-limiting breakdown of the gem-diol hydrate of HCA into trichloroacetic acid and trichloromethanide anions, followed by the more rapid decomposition of trichloroacetic acid.

The reaction of bis(2,4,6-trinitrophenyl) sulfone and some of its 3- and 3,3'-substituted derivatives with organic bases leads to the formation of an adduct of 1,3,5-trinitrobenzene or its substituted derivative and the respective amine, sulfur trioxide, and 2,4,6-trinitrodiphenylamine and its derivatives or derivatives of 2,4,6-trinitroaniline.The direction of reaction does not depend on the ratio of the initial compounds or on the temperature.It was established that attack by the nucleophilic reagent takes place at the ring in which the largest positive charge is induced at the carbon atom attached to the sulfur.

Cationic micelles of hexadecyltrimethylammonium bromide, chloride, and hydroxide (CTABr, CTACl, and CTAOH) greatly enhance the stability of anionic ?-complex formed by hydroxide ion and 1,3,5-trinitrobenzene (TNB).The counterion binding to the micellar head groups is assumed to vary but is governed by a distribution constant.Different distribution constants are used for different types of counterion.Using this treatment, the rate constant - surfactant concentration profiles for the reactions of TNB with hydroxide ion in CTAOH, CTABr, and CTACl can all be satisfactorily accounted for, yielding consistent results in various conditions.The ion distribution constants, KOH = 55 mol-1 dm3, KBr = 1800 mol-1 dm3, and KCl = 420 mol-1 dm3 and the rate constant kM = 3600 s-1 are obtained.In view of the sucess of this treatment, the assumption of a constant β value associated with the pseudophase model at best could only be viewed as an approximation, valid only for micellar systems with tightly bound counterions such as those in the micelles of CTABr.

Kinetics of decarboxylation, in water solution, of several 4-substituted 2,6-dinitrobenzoic and 2-substituted 4,6-dinitrobenzoic acids were determined, at several temperatures.The reactions are first order at the low concentrations employed, at which the acids are fully dissociated.Decarboxylation is accelerated by electron-attracting substituents; the Hammett ρ for the effects of 4-substituents is about +2.6.All the decarboxylations involve large positive enthalpies and entropies of activation.The solvent kinetic isotope effect (D2O/H2O) is not significantly different from unity.The data support a mechanism where in the substituted benzoate ion loses CO2 in the rate-determining step, forming a substituted aryl anion, which is then rapidly hydronated by the solvent.In the case of 2-methoxy-4,6-dinitrobenzoate ion, reaction occured with strikingly different activation parameters.

Hexanitrobenzene and pentanitrobenzene in benzene solution react with hydrogen halides (HCl, HBr, HI, but not HF) at 25 deg C to produce high yields of pentanitrohalobenzenes and 2,3,4,6-tetranitrohalobenzenes, respectively.Pentanitrofluorobenzene also reacts readily with HCl to yield 3-chloro-2,4,5,6-tetranitrofluorobenzene, but the other pentanitrohalobenzenes are much less reactive. 1,2,3,5- and 1,2,4,5-tetranitrobenzenes react rapidly with concentrated hydrochloric or hydrobromic acids at reflux to form picryl halides and 1-halo-2,4,5-trinitrobenzenes, respectively; pentanitrotoluene reacts very slowly under these conditions to form 3-halo-2,4,5,6-tetranitrotoluenes in lower yields.The scope and limitations of this regioselective reaction are defined, and comparison is made to related reactions.A mechanism is presented and discussed.

The reaction of picryl halides PicX (X = F, Cl, I) with organometallic compounds Me3SnM (M= Li, K, Cs), Et3GeK, borates Me4NBR4 (R = Bu, CH2SiMe3, CH2GeMe3), and 9-fluorenylpotassium was investigated.It was shown that for picryl fluoride and picryl chloride the reaction leads to the corresponding picrate.In the case of picryl iodide 1,3,5-trinitrobenzene is formed in addition to the picrate.The formation of the picrate also accompanies the reaction of PicX (X = F, Cl, I) with potassioacetoacetic ester, the main product from which is picrylacetoacetic ester.Possiblemechanisms are considered for the reaction leading to the picrates.

Kinetics of cyclicondensation reaction of acetoacetanilide and substituted acetoacetanilides with 1,3,5-trinitrobenzene in the presence of triethylamine have been studied in 75percentDMSO-water(v/v) at 30, 35 and 40 deg C.Electron donating groups accelerate the rate of the reaction.Strongly electron withdrawing groups in the para-position require the use of ?--values for a better correlation of the rate constants.The reaction constants and the resonance parameters have been calculated.Isokinetic relationship has been established.Equilibrium constants for the formationof sodium salts of bicyclononane derivatives from sodium salts of acetoacetanilides and TNB have been calculated.

Nitro-substituted arylhydroxylamines and alkyloxyamines have been oxidized to polynitroaryl compounds by utilizing ozone.Polynitroanilines have been oxidized to polynitroaromatics by peroxydisulfuric acid generated in situ from SO3 and ozone.Thus N-hydroxy-2,4,6-trinitroaniline (1a) or N-methoxy-2,4,6-trinitroaniline (1b) was cleanly oxidized to 1,2,3,5-tetranitrobenzene (2) by reaction with ozone in methylene chloride.Weakly basic amines such as pentanitroaniline (10) can conveniently be oxidized to hexanitrobenzene (11) in high yields by simply dissolving the amine in oleum and introducing ozone.A variety of substituted arylamines have been oxidized to polynitroaromatic compounds by using these two oxidation techniques.

Rate and equilibrium measurements are reported for the reactions of 1,3,5-trinitrobenzene with pyrrolidine and with piperidine in dimethyl sulphoxide (DMSO) and in a DMSO-water mixture.These reactions lead to the formation of anionic ?-adducts via zwitterionic intermediates and it is shown that proton transfer is rate-limiting or partially rate-limiting.In DMSO the rate of proton transfer is an order of magnitude faster for the reaction with pyrrolidine than for the reaction with piperidine.However, the addition of water reduces this difference.Implications for the mechanism of base catalysis in nucleophilic aromatic substitution reactions are discussed.

We have found that (i) the reaction of NADH model compounds with potassium persulphate (PPS) in anionic and non-ionic micelles initiates radical polymerisation of acrylamide and (ii) that reductive desulphonation of 2,4,6-trinitrobenzenesulphonate and 4-carboxy-2,6-dinitrobenzenesulphonate by NADH model compounds in deuterium oxide in the presence of the micelles gives 1,3,5-trinitrobenzene and 3,5-dinitrobenzoic acid, respectively, which contain 3-16percent deuterium.The results indicate that the reactions proceed through multi-step hydrogen transfer via radical ion-pair intermediates and the micelle is capable of dissociating the radical ion-pairs.

In the reduction of di- or polynitro aromatic compounds by gaseous H2 S over a solid catalyst, addition of CO gas promotes formation of amino groups from all nitro groups in the molecule. A preferred embodiment is reduction of 2,4- and/or 2,6-dinitrotoluene in vapor phase at 325° C. over a supported iron or supported cobalt catalyst on a support comprising alumina. The amino products are useful for production of polyurethane resins.

Preparation of 4,6-dinitrobenzofurazan (6) has been investigated by a number of routes.Its synthesis from 4,6-dinitrobenzofuroxan (4,6-dinitrobenzofurazan 1-oxide) (1) by reduction with triphenylphosphine proceeds in similar overall yield to the known method of nitration of 5-nitrobenzofurazan (8) but in fewer steps.Nitration of 4-nitrobenzofurazan (7) was studied as an alternative route, and the difference in reactivity between (7) and (8) is discussed.The benzofurazan (6) readily forms hydroxy and methoxy Meisenheimer complexes which have been isolated as stable, but highly explosive, potassium salts.

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