Trinitrobenzene-methoxide

Unequivocal evidence for the formation of o -adducts has been obtained by X-ray diffraction analysis of those adducts which are stable enough to obtain their single crystals [11]. Indeed, the X-ray crystallography data are available for the anionic trinitrobenzene-methoxide and the Janovsky trinitrobenzene-acetone complexes [11, 201, 202] and for the o -adducts of isoquinoline [203], phthalazine [160], and 4,7-phenanthroline [161, 162] with dialkyl phosphonates. Also the X-ray data have been obtained for the neutral o -adducts resulting from the reactions of iV-methylacridinium ion with N-nucleophiles [204, 205] and for the o -adducts of iV-alkyl-substituted 2,3-dicyanopyrazinium and quinoxalinium salts with 0-, C-and P-nucleophiles [163, 194]. 

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). 

Solutions of 1,3,5-trinitrobenzene in methanol containing sodium methoxide are orange-coloured. The visible spectrum with maxima at... 

Addition of methoxide ion in methanol For reactive substrates, such as 1,3,5-trinitrobenzene, which are converted into complex in dilute solutions of sodium methoxide, the equilibrium constant, Kx, is adequately expressed in terms of concentrations as [A]/[P][OMe-]. However, for less reactive substrates, such as dinitrobenzenes, significant conversion to complex only occurs at fairly high concentrations of sodium methoxide similarly for the higher equilibria of trinitro-substituted benzenes. In these solutions the basicity of the medium cannot be adequately described by the con-... 

The greater stability of the 1 1 adducts in aprotic solvents is, then, attributed mainly to the enhanced reactivity of the attacking nucleophiles in these solvents. This factor should also favour the production of di-adducts in aprotic solvents and NMR measurements do indicate that these are formed from trinitro-substituted compounds and methoxide ions in media rich in dimethyl sulphoxide. However, there is some evidence that the di-adducts are not particularly well solvated by dimethyl sulphoxide and are in fact better solvated by water. Thus it has been found that 1 2 adducts are very readily formed in water. For example 1,3,5-trinitrobenzene gives both 1 1 and 1 2 adducts in fairly dilute solutions of hydroxide ions in water, while dimethyl-picramide and the picrate ion give evidence only for the production of 1 2 adducts. Similarly a variety of trinitro-compounds are readily converted into di-adducts in aqueous sodium sulphite solution, although... 

Picramide reacts with sodium methoxide in the same manner as trinitrobenzene, forming coloured solutions. Some solid salts have been prepared by Busch and Kogel [17], Recently Farmer [18] found that the coloured compound I can be obtained by two methods ... 

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... 

As early as 1895 Lobry de Bruin [22] described a red solid which he isolated m the reaction of 13>5-trinitrobenzene with potassium hydroxide in methanol. [Ileyer [23] suggested this to be a complex compound. Hantzsch and Kissel ) rationalized that the complex might be a potassium salt of aci-form of one group. Jackson and Gazzolo [25] suggested in 1900 two structural formulae the sodium salt obtained by acting with sodium methoxide on 2,4,6-trinitro-il Fig. 1 Sa. Meisenheimer [26] (probably unaware of Jackson s paper)... 

Evidence for the formation of Meisenheimer, or a a-complex, involving aniline as a nucleophile has been presented with 1,3,5-trinitrobenzene (TNB) by Buncel and coworkers107. Reactions of the TNB-methoxide ion adduct with a series of substituted anilines in DMSO solution yield new TNB-aromatic amine o-complexes (Scheme 12). 

Nucleophilic displacement. One nitro group of 1,3,5-trinitrobenzene is displaced by raethoxyl on brief refluxing with sodium methoxide in methanol. ... 

Addition of methoxide ion in methanol For reactive substrates, such as 1,3,5-trinitrobenzene, which are con-... 

The first such intermediate was isolated by Meisenheimer in 1902 from the reaction of 2-ethoxy-1,3,5-trinitrobenzene with sodium methoxide ... 

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