Nitromethane extraction

In view of the small volume of nitromethane to be manipulated, the crude nitromethane may be extracted from the aqueous distillate with ether (30-40 ml.). Dry the ethereal extract over sodium sulphate, filter through a fluted filter-paper, and then distil off the ether on a water-bath with the usual precautions (Fig. 64, p. 163 Fig, 23(E), p. 45) finally distil the residual nitromethane. 

Eichler and Wahl have attempted an isotopic study ( Os and Os) of the exchange reaction between Os(dipy)3 and Os(dipy)3 using a direct injection technique so that reaction times 7 x 10 sec were possible. With total osmium 10" M in aqueous sulphate media at 0 °C complete exchange was observed. The separation methods used were, (a) perchlorate precipitation (in presence of iron(II) carrier) and (6) extraction with p-toluenesulphonic acid in nitromethane, of the osmium(II) complex. A lower limit of 1 x 10 l.mole. sec was placed on the rate coefficient (0 °C, 3.0 M H2SO4). Dietrich and Wahl using the line broadening effect produced by Os(dipy)3 on the nmr spectrum of Os(dipy)3 have been able to propose a value of > 5x 10" l.mole . sec at 6 °C in D2O (0.14 M [Cr] and 5x10 M [D- ]). 

The oxime (an isomer of ethylnitrolic acid ) decomposes gradually at ambient temperature, but explosively above 110°C [1], The product from treatment of nitromethane with strong sodium hydroxide solution at 50°C, followed by acidification and ether extraction, gave, after vacuum evaporation, a residue which exploded when air was admitted. On this occasion, a weekend elapsed between alkali and acid treatments, and it seems possible that formation of fulminic acid derivatives may have occurred [2], A 75 g sample of methazonic acid, from a preparation which had transiently overheated to 70°C, during the addition of nitromethane to sodium hydroxide solution, was stored for a week at — 15°C, then allowed to warm to room temperature. Twelve hours later it spontaneously detonated, destroying a fume hood. There is no evident cause for this explosion [3], It seems sensible to... 

HNO, (10%, 16 ml, 25 mmol) and TBA-AuCl4 or TBA-AuBr4 (0.25 mmol) are added to the dialkyl sulphide (5 mmol) in nitromethane (8 ml). The initially colourless solution is stirred until a yellow colour persists. Aqueous Na2S20, (sat. soln. 10 ml) is then added (for basic substrates, Na,CO, is also added to make the mixture alkaline). The mixture is extracted with CH2Cl2 (2 x 25 ml) and the dried (Na2S04) extracts are evaporated to yield the sulphoxides. 

The class of nitrolic acids (nitro-oximes) was introduced by Victor Mayer as early as 1873 with the simplest representative methylnitroUc acid (HC(N02)=N0H) °. Tscher-niak, a student of Mayer, was the first to isolate the very labile methylnitroUc acid at low temperatures, while Wieland improved the synthesis by detailing the exact reaction conditions to increase the low yields. MethylnitroUc acid can be prepared as crystalline solid from nitromethane and KNO2/H2SO4 in situ generation of nitrous acid) in water at low temperatures, followed by extraction from this weak acidic solution into ether (Scheme 17). Removal of ether yields the pme, highly unstable free acid. Salts of methylnitroUc acid, NNtM, can be generated by extracting the acid into sodium carbonate solution. ... 

COj -48.5%, OB to CO -12.1%. Plates, unstable, mp 55 62° with decompn very sol in w eth, in sol in ligioin. Was prepd by mixing acetone with nitric acid(dl. 14) and a little fuming HNO, and allowing the mixt to stand for 8 days at RT. An ether extraction gave on e-apcm seme acstylmethyi-nitrolic acid(Refs 1 2). Krauz Stepanek (Ref 3) attempted and failed to prep tetra-nitromethane by nitration of acet. Instead, they obtd (after treating the nitrated prod with silver salt) an expl compd claimed to be the Ag salt of acetylmethylnitrolic acid, CHj, , CO. C(NOj). N. 0 Ag (see also Acetone, Nitration)... 

The infrared (IR) spectra of 1,10-phenanthroline, its hydrate and perchlorate in the region 600-2000 cm-1 have been obtained, and the principal features of the spectra interpreted.66 Further studies on the IR spectra of 1,10-phenanthroline,67-69 substituted 1,10-phenanthrolines,70,71 and 1,7-phenanthroline67 have also been reported. The IR spectrum of 4,7-phenanthroline in the region 650-900 cm-1 has been analyzed, and the C—H out-of-plane deformation frequencies were compared with those of phenanthrene and benzo[/]quinoline.72 The IR spectra of salts of 1,10-phenanthroline have been taken, and the NH vibrations determined.28,73 Infrared spectroscopy has been used to detect water associated with 1,10-phenanthroline and some of its derivatives on extraction into nitromethane from aqueous solution.74 The Raman spectrum of 1,10-phenanthroline has been compared with its IR spectrum.75 Recently, the Raman and IR spectra of all ten isomeric phenanthrolines were measured in solution and solid states, and the spectra were fully discussed.76... 

The mother liquors were diluted with H20, and extracted with 3x100 mL CH2C12. The pooled extracts were washed with 5% NaOH, and the solvent removed under vacuum yielding 34 g of a dark residue that was largely unreacted aldehyde. This residue was reprocessed in acetic acid with nitromethane and ammonium acetate, as described above, and provided an additional 8.1 g of the nitrostyrene with the same mp. 

The mixture of 5 mmol of benzylidene methylcyanoacetate la and 15 mmol of nitromethane adsorbed over alumina was placed in a quartz tube and introduced into Syntliewave 402 microwave reactor with a temperature monitored at 90 °C obtained after 3 and maintained 9 min. The mixture was cooled down and extracted with CH2CI2. After filtration of A1203 and removal of the solvent the pure product 3a (two diastereomers A/B, 50 50) was isolated by crystallization from cold ether. 

Nitromethane 2a (1.2 mmol), alumina (1 g, basic activated at 200 °C) and benzal-acetophenone 1 (1.2 mmol) were mixed together without solvent in an Erlen-meyer flask and placed in a commercial microwave oven (operating at 2450 Hz frequency) and irradiated for 18 min. The reaction mixture was allowed to reach room temperature and extracted with chloroform. Removal of solvent and the re-... 

Even for barriers as high as 3.5kcal/mol, when 0 — 200 cm"1, (2) — 0.2 rad, so that zero-point linear displacements of H atoms are 0.20-0.22 A. Thus, the torsion vibrations, unlike stretching modes, are really motions with wide amplitudes in the full sense of these words. The temperature dependence of can be found in the harmonic approximation using (2.82) experimentally, it can be extracted from the temperature dependence of the width of INS peaks assigned to torsion vibrations. As a typical example of this dependence, the results of Trevino et al. [1980] for deuterated nitromethane crystal are represented in Figure 7.8. 

The last compound was prepared as follows the hydroxyl groups of 3,4-dihydroxy-benzaldehyde was protected using t-butyldimethylsilylchloride (1). 100 mg (0.26 mmol) of 3,4-di(t-butyl-methylsiloxy)benzaldehyde was dissolved in 1 ml tetrahydrofurane under atmosphere of argon at -40°C, and 0.30 ml of metal complex from (S)-6,6 -bis(triethylsilylethynyl)-l,l-dihydroxy-2,2 -binaphtalene (2) mixed with a solution of n-butyllitium in hexane.After stirring for 30 minutes, 79.4 mg (1.3 mmol) of nitromethane was added dropwise to the mixture. After 67 hour reaction time, 2 ml of 1 N aqueous solution of hydrochloric acid added to stop the reaction. Product was extracted with 50 ml ethyl acetate, dehydrated with anhydrous sodium sulfate and concentrated within evaporator followed by silica gel chromatography (n-hexane/acetone = 10/1), after which (R)-l-(3,4-di(t-butyldimethylsiloxy) phenyl)-2-nitroethanol with an optical purity of 92% e.e. was obtained in a yield of 93%. 

A solution of 27.6 g (0.16 mol) of freshly distilled ethyl 7-aminoheptanoate in 40 ml of nitromethane was added all at once and with mechanical stirring to a suspension of 26.2 g (0.08 mol) of 5,8-dichloro-10-dioxo-ll-methyldibenzo[c,f]thiazepine(l,2) in 120 ml of nitromethane. The whole was heated to 55°C for 30 minutes, the solvent was then evaporated in vacuo and the residue was taken up in water. The crude ester was extracted with ether. After evaporation of the ether 36 g of crude ester were obtained, and 30 g (0.065 mol) there of were treated under reflux with a solution of 2.8 g (0.07 mol) of sodium hydroxide in 35 ml of ethanol and 25 ml of water. After one hour s refluxing, the alcohol was evaporated in vacuo. The residue was taken up in 150 ml of water. 

The Soxhlet extraction of particles with benzene-methanol yielded PAHs plus many polar and non-polar organic compounds which interfered with the gas chromatographic separations. The interfering compounds were removed using standard solvent partitioning with dimethyl sulfoxide [DMSO] (10), dimethylformamide [DMF] (11), or nitromethane (12). 

A mixture of Yb(OTf)3 (620 mg, 1 mmol), anisole (1, 540 pL, 5 mmol), and acetic anhydride (940 pL, 10 mmol) in nitromethane (5mL) was stirred at 50 °C for 4h. After dilution with water (10 mL), the mixture was extracted with dichlorometh-ane. The organic layers were combined and dried over NaS04. After filtration and evaporation of the solvents, the crude mixture was purified by column chromatography on silica gel to afford 4-methoxyacetophenone (2). The aqueous layer was concentrated in vacuo to give a crystalline residue, which was heated at 190 °C for 4h in vacuo to afford 576.6 mg (93 %) Yb(OTf)3 as colorless crystals. The recovered Yb(OTf)3 was reused in the next acylation reaction. All products of the acylation of aromatic compounds shown in this chapter are known compounds and are commercially available. 

The product from Step 1 (16.2 mmol) was dissolved in 10 ml THE, added to nitromethane (35.2 mmol) and 22 ml 1 M BU4NE in THE, and stirred at 70°C 6 hours. The mixture was cooled to ambient temperature and extracted with 50 ml EtOAc. The extract was treated with 30 ml HCl, 50 ml brine, and the product isolated as in Step 1 in 29% yield. IR, MS, and H-NMR data supplied. 

The product from Step 2 (58.6 mmol) dissolved in 140 ml DMF was added to a solution of sodium methoxide (174 mmol) containing nitromethane (128 mmol) in 140 ml DMF over 80 minutes. The mixture was stirred for 20 minutes then poured into 1 L water and the pH adjusted to 7 using dilute HCl. Thereafter, the mixture was extracted 4 times with 500 ml EtOAc and concentrated under reduced pressure. The mixture was purified by chromatography on silica gel using CH2Cl2/EtOAc, 2 1, and the product isolated in 56% yield, mp = 160-163°C. H-NMR and IR data supplied. 

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