1.3- Dinitro compounds synthesis

Alcantara, M.-P.D., Dianez, M.J., Escribano, F.C., Estrada, M.D., Gomez-Sanchez, A., Lopez-Castro, A., and Perez-Garrido, S. 1996. Synthesis of aliphatic 1,3-dinitro compounds. Synthesis, 1 64-70. 

In 1971, Komblum and coworkers reported a new synthesis of rerrn-snbstituted alkenes from vicinal dinitro compounds.The requisite vicinal dinitro compounds are prepared by the... 

Ono and coworkers have extended the radical elimination of v/c-dinitro compounds to P-nitro sulfones151 and P-nitro sulfides.138,152 As P-nitro sulfides are readily prepared by the Michael addition of thiols to nitroalkenes, radical elimination of P-nitrosulfides provides a useful method for olefin synthesis. For example, cyclohexanone is converted into allyl alcohol by the reaction shown in Eq. 7.110. Treatment of cyclohexanone with a mixture of nitromethane, PhSH, 35%-HCHO, TMG (0.1 equiv) in acetonitrile gives ahydroxymethylated-P-nitro sulfide in 68% yield, which is converted into the corresponding allyl alcohol in 86% yield by the reaction with Bu3SnH.138 Nitro-aldol and the Michael addition reactions take place sequentially to give the required P-nitro sulfides in one pot. 

Reductive carbonylation of nitro compounds (in particular aromatic dinitro compounds) is an important target in industry for making diisocyanates, one of the starting materials for polycarbamates. At present diisocyanates are made from diamines and phosgene. Direct synthesis of isocyanates from nitro compounds would avoid the reduction of nitro compounds to anilines, the... 

For aromatic or heteroaromatic monoaldehydes, ArCHO, an efficient procedure has been developed for synthesis of 1,3-dinitro compounds [132]. Rather than in situ reduction of O2, the O2 reduction is carried out in a divided cell with the aliphatic nitro compound as the solvent. Charge corresponding to 0.5 F with respect to the aldehyde is passed through the cell, the current is switched off... 

The Ponzio reaction provides a useful route to gem-dinitro compounds and involves treating oximes with a solution of nitrogen dioxide or its dimer in diethyl ether or a chlorinated solvent. The Ponzio reaction works best for aromatic oximes where the synthesis of many substituted aryldinitromethanes have been reported. Compound (56), an isomer of TNT, is formed from the reaction of dinitrogen tetroxide with the oxime of benzaldehyde (55) followed by mononitration of the aromatic ring with mixed acid. Yields are usually much lower for aliphatic aldoximes and ketoximes. " The parent carbonyl compound of the oxime is usually the major by-product in these reactions. 

Nitronate salts and the tautomeric act-form of nitroalkanes, known as nitronic acids, are converted to gem-dinitro compounds on treatment with dinitrogen tetroxide. Novikov and co-workers synthesized phenyldinitromethane by treating phenylnitromethane with dinitrogen tetroxide in ether and later reported the synthesis of some substituted phenyltrinitromethanes from the direct nitration of the nitronate salts of phenylnitromethanes. 

Oxidative nitration is not effective for the synthesis of m-dinitroaliphatic compounds containing an electron-withdrawing group a to the carbon bearing the nitro groups. Oxidative nitration is not successful for the conversion of terminal em-dinitro compounds into 1,1,1-trinitromethyl derivatives. 

In the utilization of petroleum oils in the field of chemical weed control, oils function as toxicants, as solvents, as filming agents, and as carriers. In view of the very effective synthetic compounds now used as toxicants (substituted phenols), the toxicity of the oils themselves is somewhat less important than it once was. Oils may serve as adjuvants in formulations involving 2,4-D, 2,4,5-T, dinitro compounds, trichloroacetates, and others. They have the unique property of aiding in the contact, spreading, and penetration of herbicides. In addition, synthesis of wetting agents, emulsifiers, and special herbicides may be dependent on petroleum products. 

Nitration of indolizines is seldom attempted in view of accompanying oxidation reactions. Thus the synthesis of 6- and 8-nitro-2-phenyl-indolizine has been achieved by the cyclization of appropriately substituted 2-methyl-1-phenacylpyridinium bromide.179 However, 1-nitro and 1,3-dinitro compounds have been prepared.4 From the behavior of the indolizine nucleus toward other electrophiles, 3-nitroindolizine might be expected to be the primary product. This compound has been synthesized using a dilute solution of nitric acid in acetic acid at - 70°C where the substrate could well be the base and not the 3-protonated cation as in a nitric acid-sulfuric acid mixture.180... 

Only the synthesis of the mono-nitro species 54 but not the one of the corresponding dinitro-compound succeeded. In the latter case, the tetrahydropy-rene-derivative 56 forms by removal of the intraannular groups. 

Olefin synthesh. Komblum ei a . have described a new synthesis of tetrasubsti-tuted olefins from vicinal dinitro compounds. There are several methods for conversion of aliphatic and alicyclic nitro compounds into nic-dinitro compounds, the most useful of which is a procedure of Seigle and Hass. A nitroparafhn is converted into (he lithium salt (I) by treatment with lithium methoxidc and this is then treated with bromine to form a bromonilro compound (2). Reaction of (2) with a second equivalent of the nitro-R.. NO,, ... 

Problem 24.8 The //-propyl ether of 2-amino-4-nitrophenol is one of the sweetest compounds ever prepared, being about 5000 times as sweet as the common sugar sucrose. It can be made from the dinitro compound by reduction with ammonium bisulfide. Outline the synthesis of this material starting from benzene or toluene and any aliphatic reagents. 

Niazimbetova ZI, Evans DH, Liable-Sands LM, Rheingold AL (2000) Electrochemical synthesis of aliphatic 1,3-dinitro compounds. J Electrochem Soc 147 256-259... 

Selective hydrogenation of one or two nitro groups in an aromatic dinitro compound is the basis for the synthesis of otherwise unattainable molecules. Carefully chosen catalysts, under totally different reaction conditions, have been met with success. Partial reduction of 2,6-dinitroanilines to nitrophenylenediamines occurs in 60-90% yield over 10% palladium-on-carbon at RT [equation (a)], although most heterogeneous catalysts do not afford such selectivity. 

The compound nitralin (SD 11831, 11) was first described by Soloway and Zwahlen (1966). Its synthesis starts with 4-chiorophenyl methyl sulfone, which is nitrated with a fuming sulfuric acid-fuming nitric add mixture to the dinitro compound. This then reacts with dipropylamine to give nitralin ... 

Nitration studies on a series of 3-methyl- and 3-ethylindoxazenes have been recorded.12 3-Methyl- and 3-ethylindoxazene yield a mixture of the 5-nitro and 5,7-dinitro derivatives. If the 5-position is blocked (e.g., by chloro or alkyl groups) then, surprisingly, nitration takes place at the 4-position. As expected, the 7-chloro-3-alkyl and the 3,7-dialkyl derivatives are nitrated exclusively at the 5-position, whereas the 3,6-dialkyl and 3-alkyl-6-chloro derivatives yield a mixture of the 5-nitro and 5,7-dinitro compounds. The structures of the nitro compounds were confirmed by H-NMR spectroscopy and, in some instances by synthesis from the nitro-substituted ketoxime acetates (see Section II,A,2). 

Alkene synthesis from lc-dinitro compounds. In the original synthesis (4, 460-461), sodium sulfide (or sodium thiophenoxide) was used as the reducing agent. This method, however, does not tolerate various functional groups ester, keto, cyano, or ether. This defect can be remedied by use of calcium amalgam, which reduces nitro groups more readily than other common functional groups. Examples ... 

Won et al. [19], have reported synthesis of polyesters with valine, leucine, isoleucine, methionine, and phenylalanine (Table 12.1). This three-step process involves synthesis of a diester and a dinitro compound that are copolymerized [19], An amino acid is first coupled with a diol (with 3, 4, or 6 methylene groups) in the presence of tosyl to yield a diester with acid salts of diamine at the terminal ends. The second monomer, di-p-nitrophenyl ester of carboxylic acids, is synthesized by a condensation reaction of adipoyl or se-bacoyl chloride with p-nitro phenol. The final polymerization step involves an arduous condensation reaction in the presence of a strong proton abstractor between acid salt of bis(amino acid-alkyne diester) and di-p-nitrophenyl ester of dicarboxylic acids. Following along the same lines, Chu and Guo [22] have copolymerized a mixture of nitro phenyl ester of succinate, adipate, or sebacate and nitrophenyl fumarate with toluenesulfonic acid salt of phenylalanine butane-1,4-diester. The addition of fumarate derivative to the monomer mixture provides an unsaturated double bond in the polymer backbone that can be functionalized for specific biomedical... 

Early DNPOH synthesis methods include nitrification oxidization method, chlorination nitration method and electrochemical method. In 1961, Kaplan et al. [37] proposed a reaction with a redox process to synthesize gem-dinitro compounds, in which nitro ethane, as the raw materials, reacts with formaldehyde in the presence of sodium hydroxide, followed by the synthesis of DNPOH through the nitration reaction of silver nitrate and sodium nitrate. The reaction mechanism is ... 

Vytautas G, Garver LC, Kurt B (1990) Synthesis of geminal dinitro compounds. US Patent 4,910,322, 1990... 

Synthesis of N,N,-bis(4-aminohenyl)-N, N -bis[4-(2-phenyl-2-isopropyl) phenyl]- ,4-phenylene-diamine (4). The dinitro compound (3) (5 g, 6.77 mmol ), Pd/C (0.2 g), and 150 ml ethanol were taken in a three-necked ttsk and hydrazine monohydrate (10 ml) was added drop wise over a period of 30 min at 90°C. Upon completing the addition, the solution was stirred at re Dux temperature for 12 hr. After the solution was cooled down to room temperature, the solution was Eltered to remove the catalyst, and the crade product was puriCbd by silica gel column chromatography ( -hexane ethyl acetate = 2 1) to afford diamine monomer (4) 2.3 g fyield 50%), mp 149-15 PC by DSC (10°C/min). 

The synthesis of 2-monosubstituted or 2,2 -disubstituted precursor compounds can be achieved by two different routes direct electrophilic aromatic substitution or the use of substituted derivatives of 9-fluorenone. hi many cases, the first route is complicated due to the fact that the two fluorene moieties in spirobifluorene react chemically independently of each other. The formation of products monosubstituted in the 2-position is therefore often accompanied by the formation of byproducts (Fig. 6). A good example is the nitration of spirobifluorene, which was investigated by Weisburger and coworkers [23]. They discovered that a careful control of reaction times and conditions allowed for the formation of 2-nitro-9,9 -spirobifluorene or 2,2 -dinitro-9,9 -spirobifluorene as the main product. Especially in the case of 2-nitro-9,9 -spirobifluorene, however, the conversions are low because the reaction must be quenched before a suitable amoimt of the dinitro compound is formed. 

The nucleophilic displacement polymerization reaction is more common for the synthesis of PAEs because of the easy accessibility of monomers and high yield of high-molecular-weight polymers. Nucleophilic displacement of an activated dihalo or dinitro compound with an activated bisphenol (mostly in the form of bisphenoxides) at high temperatures has been the most common method of PAE synthesis [35,37,39], The reaction is conducted in solution using different otic solvents, for example, V-methyl-2-pyrrolidone (NMP), V,V-dimethyl acetamide (DMAc), or dimethyl sulfoxide (DMSO). 

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