- Synthesis of hexanitrostilbene (HNS) using a kenics static mixer
-
Previous work on a Shipp-Kaplan type synthesis of hexanitrostilbene (HNS) using a Kenics static mixer (ref1, from Chemineer Ltd., Cranmer Road, West Meadows, Derby DE21 6XT, UK; www.chemineer.com) has been extended by using a larger mixer (9.5 mm vs 4.75 mm OD), enabling the scale to be increased from 2.5 g to 25 g of trinitrotoluene (TNT) for the same mixing time (2SO4 and NaOH solutions, and (iii) pH control using aqueous RNH3Cl and RNH2 solutions. Other parameters that have been varied are the ratio of NaOCl to TNT (0.5-1.2) and the concentration of both reactants. The yields of crude HNS that have been achieved, whilst not outstanding, are an improvement over the conventional batch process. It has been demonstrated that the yield and selectivity of the HNS synthesis can be considerably increased if, during the after-reaction period, the reaction conditions are pH controlled. The yield and selectivity are also significantly enhanced by using more dilute reaction solutions.
- Bellamy, Anthony J.
-
experimental part
p. 632 - 639
(2011/07/09)
-
- Chemoenzymatic Synthesis of Trinitrobenzyl Halides as an Alternative Approach to Hexanitrostilbene
-
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.
- Munir, Inmar Z.,Hu, Shanghui,Dordick, Jonathan S.
-
p. 1097 - 1102
(2007/10/03)
-
- Radical ion reactions of carbanions derived from 4-nitro-, 2,4-dinitro-, and 2,4,6-trinitrotoluenes with polynitroalkanes
-
4-Nitro-and 2,4-dinitrotoluenes react with tetranitro-and halotrinitromethanes in the presence of bases to give the corresponding nitro-substituted 1,2-diphenylethanes and stilbenes. Reactions of 2,4,6-trinitrotoluene with fluorotrinitromethane, N,N-dinitrotnethylamine, and tert-butyl and isopropyl nitrates result in formation of α,2,4,6-tetranitrotoluene; with chlorotrinitromethane, 2,4,6-trinitrobenzyl chloride is formed.
- Makarevich,Shcherbinin,Bazanov,Tselinskii
-
p. 684 - 692
(2007/10/03)
-
- The Stabilities of Meisenheimer Complexes. Part 29. The Reactions of 2,4,6-Trinitrotoluene and 2,4,6-Trinitrobenzyl Chloride with Aliphatic Amines in Dimethyl Sulphoxide
-
Kinetic and spectroscopic studies have been made of the reactions in dimethyl sulphoxide of 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrobenzyl chloride (TNBCl) with the amines n-butylamine, isopropylamine, benzylamine, piperidine, and 1,4-diazabicyclooctane.Two processes have been identified, ?-adduct formation and transfer of a side-chain proton.Kinetic and equilibrium data relating to the latter reaction show that the rate of the proton transfer from substrate to amine is relatively insensitive to the nature of the reagents, indicating a reactant-like transition state.The ?-adducts formed from TNBCl and the primary amines are thought to result from attack at the 1-position, while those formed from TNBCl and piperidine or from TNT probably involve attack at the 3-position.Equilibrium constants for these reactions have been determined.
- Brooke, David N.,Crampton, Michael R.
-
p. 231 - 238
(2007/10/02)
-
- The Stabilities of Meisenheimer Complexes. Part 21. Sulphite Additions to 2,4,6-Trinitrotoluene and 2,4,6-Trinitrobenzyl Chloride
-
In aqueous sodium sulphite solutions, 2,4,6-trinitrotoluene and 2,4,6-trinitrobenzyl chloride give 1:1 and 1:2 adducts by addition at unsubstituted ring positions.Rate and equilibrium data for these reactions have been obtained by the stopped-flow method and are compared with similar data for other nitro-compounds.
- Brooke, David N.,Crampton, Michael R.
-
p. 1850 - 1853
(2007/10/02)
-