Nitrobenzene formamide

The importance of the solvent, in many cases an excess of the quatemizing reagent, in the formation of heterocyclic salts was recognized early. The function of dielectric constants and other more detailed influences on quatemization are dealt with in Section VI, but a consideration of the subject from a preparative standpoint is presented here. Methanol and ethanol are used frequently as solvents, and acetone,chloroform, acetonitrile, nitrobenzene, and dimethyl-formamide have been used successfully. The last two solvents were among those considered by Coleman and Fuoss in their search for a suitable solvent for kinetic experiments both solvents gave rise to side reactions when used for the reaction of pyridine with i-butyl bromide. Their observation with nitrobenzene is unexpected, and no other workers have reported difficulties. However, tetramethylene sulfone, 2,4-dimethylsulfolane, ethylene and propylene carbonates, and salicylaldehyde were satisfactory, giving relatively rapid reactions and clean products. Ethylene dichloride, used quite frequently for Friedel-Crafts reactions, would be expected to be a useful solvent but has only recently been used for quatemization reactions. ... 

FIGURE 8 Analysis of the test mixture with (A) the SDS MEKC system containing 10 mM phosphate buffer (pH 7.5), 60 mM SDS, and 10% acetonitrile and (B) the CTAB MEKC system containing 25 mM phosphate buffer (pH 7.5), 10 mM CTAB, and 10% acetonitrile. Peaks I formamide 2 pyridine 3 aniline 4 meta-cresol 5 phenyl acetate 6 nitrobenzene 7 benzoic acid 8 thiamine 9 ethyl benzoate. (Reprinted from reference 270, with permission.)... 

Figure 18. Correlations between the solubility of cmchonidme and the reported empirical polarity (A) and dielectric constants (B) of 48 solvents [66]. Those solvents are indicated by the numbers in the figures 1 cyclohexane 2 n-pentane 3 n-hexane 4 triethylamine 5 carbon tetrachloride 6 carbon disulfide 7 toluene 8 benzene 9 ethyl ether 10 trichloroethylene 11 1,4-dioxane 12 chlorobenzene 13 tetrahydrofuran 14 ethyl acetate 15 chloroform 16 cyclohexanone 17 dichloromethane 18 ethyl formate 19 nitrobenzene 20 acetone 21 N,N-drmethyl formamide 22 dimethyl sulfoxide 23 acetonitrile 24 propylene carbonate 25 dioxane (90 wt%)-water 26 2-butanol 27 2-propanol 28 acetone (90 wt%)-water 29 1-butanol 30 dioxane (70 wt%)-water 31 ethyl lactate 32 acetic acid 33 ethanol 34 acetone (70 wt%)-water 35 dioxane (50 wt%)-water 36 N-methylformamide 37 acetone (50 wt%)-water 38 ethanol (50 wt%)-water 39 methanol 40 ethanol (40 wt%-water) 41 formamide 42 dioxane (30 wt%)-water 43 ethanol (30 wt%)-water 44 acetone (30 wt%)-water 45 methanol (50 wt%)-water 46 ethanol (20 wt%)-water 47 ethanol (10 wt%)-water 48 water. [Reproduced by permission of the American Chemical Society from Ma, Z. Zaera, F. J. Phys. Chem. B 2005, 109, 406-414.]...

Nitrobenzene radical-anion is more stable in aprotic solvents than its aliphatic counterparts. Nitrobenzene shows two one-electron polarographic waves in acetonitrile with By, -1,15 and -1.93 V vj. see, Tire first wave is due to tlie formation of the radical-anion and this species has been characterised by esr spectroscopy [6]. Nitrobenzene radical-anion can also be generated in steady-state concentration by electrochemical reduction in aqueous solutions at pH 13 [7] and in dimethyl-formamide [8]. It is yellow-brown in. solution with A., ax 435 nm. Protonation initiates a series of reactions in which niti osobenzene is formed as an intermediate and... 

DMSO dimethyl sulfoxide DMF N, N-dimethylformamide FA formamide EG ethylene glycol THF tetrahydrofuran MeOH methanol PC propylene carbonate PhCN benzonitrile MeN02 nitromethane PhN02 nitrobenzene. 

The detailed mechanism of sarcosine NCA polymerisation may be radically modified by a change of solvent. For example, in dimethyl formamide this reaction is first order with respect to growing ends [see e. g. ref. (44)] instead of being second order as in nitrobenzene. The higher acidity of the former solvent reduces the basicity of the dissolved amine and, therefore, destroys its catalytic action. This effect influences also the equilibrium between the amine and the dissolved C02. In nitrobenzene, the carbamic acid produced is associated with the free amine forming the respective ammonium salt (ion-pairs), whereas in the more acidic dimethyl formamide it exists as an un-ionised acid. 

Fig. 10. Conversion-time curves for polymerisation of NCA s in 80% nitrobenzene —20% N-inethyi formamide mixture 26° C. [NCA] — 0.109 mol. I"1 Initially in all cases, (a) y-benzyl-L-gtutamate NCA [sodium dl-hydrocinnamate = 4.6 x 10 mol 1-J (b) DL-phenylalanineNCA [sodiumdihydrocinnamate] — 4.6 x 10 moll-1 (c) DL-phenylalanine NCA [sodiumhydantoin 3-acetate] = 9.2 x 10 moll-1. 100% evolution of CO . [Reprinted from paper by D. G. H. Ballard and C. H. Bamford Special Publication of Chem. Soc.

Nitrogen trifluoride Difluoramine Nitrous acid Nitric acid Cyano fluoride Formyl fluoride Carbonyl fluoride Acetyl fluoride Acetyl cyanide Isocyanic acid Methyl isocyanate Formamide Nitromethane Nitrobenzene... 

Compound 9 is prepared by 1 2 chromation in organic medium [12] Diazo-tized l-amino-2-hydroxy-4-nitrobenzene is coupled with 1-phenyl-3-methyl-5-pyrazolone. The resulting azo dye is heated at 110 °C in a mixture of formamide and a aqueous solution of chromium(m) formate. After completion of chromation, the dye 9 [64560-69-6] is precipitated with water. 

Fig. 9. MMCT band energies vs 1 /Dop - 1/DS. Key to the solvents BN, benzonitrile NB, nitrobenzene DMSO, dimethyl sulfoxide DMF, dimethylformamide DMA, dimeth-ylacetamide PC, propylene carbonate FA, formamide NM, nitromethane. [Reproduced with permission from Ref. (112). Copyright (1987) American Chemical Society.1...

U8. Popkie, H. E., and Kaufman, Joyce J., "Molecular Calculations with the VRDDO, MODPOT and MODPOT/VRDDO Procedures. . HF, F2, HC1, CI2, Formamide, Pyrrole, Pyridine and Nitrobenzene," Int. J, Quantum Chem. Symp. Issue (1976), 10, U7 —57 ... 

There will be some exceptions to these rules, but a good rule of thumb is like dissolves like . In this respect, solvents fall into three classes (a) protic solvents such as methanol and formamide which are hydrogen bond donors, (b) dipolar aprotic solvents (e.g., acetonitrile, nitrobenzene) with dielectric constants greater than 15 but which cannot form hydrogen bonds with the solute and (c) aprotic solvents in which the dielectric constant is weak and the solvent is non-polar, e.g., pentane or benzene. 

Plastic solid, d 1.406 n 1.54. Stabilizers are necessary to prevent discoloration from exposure to light or heat. Solvents for unmodified polyvinyl chloride of high mol wt cyclohexanone, methyl cyclohexanone, dimethyl formamide, nitrobenzene, tetrahydrofuran, isophorone, mesityl oxide. Solvents for lower polymers dipropyl ketone, methyl amyl ketone, methyl isobutyl ketone, acetonylacetone, methyl ethyl ketone, dioxane, methylene chloride. 

Non-hydrogen-bonded liquids of high dielectric constant are often referred to as dipolar aprotic solvents. Nitrobenzene, V,V-dimethyl-formamide, acetonitrile, and nitromethane have dielectric constants in the range 35 to 38, close to that of methanol. The dielectric constants of sulpholane, dimethylsulphoxide and propylene carbonate are higher. Any peculiarities of acid-base behaviour in dipolar aprotic solvents as compared with methanol cannot be accounted for on the basis of the Born sphere-in-continuum model. 

Non-aqueous measurements of conductances at different temperatures and pressures have so far been reported for several electrolytes, notably tetraalkylammonium salts, in methanol, dimethyl-formamide, nitrobenzene, and acetone. It has been shown " that Ep, Ey and but not are additive functions... 

BuiN+BPhi- Fuoss and Hirsch (1960), propylene carbonate, nitrobenzene Brown and Fuoss (1960X acetonitrile, /-butyronitrile Coetzee and McGuire (1963), acetone, several nitriles e 1.067, methanol 1.131 formamide 1.053, acetonitrile 1.079, nitromethane 1.157, DMSO 0.93, water ... 

Trifluoroacetic acid, acetone, acetonitrile, acrylonitrile, aniline, benzaldehyde, m-cresol, cyclohexanone, N,N-dimethyl acetamide, N,N-dimethyl formamide, dimethyl sulfoxide, ethanol amine, formic acid, N-methyl-2-pyrolidone, nitrobenzene, propylene carbonate, pyridine, triethyl phosphate... 

Nitroanthranilic acid (60 g) and 120 g freshly distilled formamide were heated in an open beaker in an oil bath at an inside temperature of 155-160°C for 6 h. The dark residue, after cooling, was pulverized and washed with 5% NaHC03 solution, then with water, and dried to afford 42 g crude 8-nitroquinazolone-4, in a yield of 67%, m.p. 240-248°C. The crude product was then recrystallized from nitrobenzene (100 mL per 15 g product) with a liberal use of charcoal for decolorization. The crystal was washed with ether to remove residual nitrobenzene, and pale yellow needles were obtained, which melted at 250-251°C. 

Diethylamine Miscible Dieth ether Miscible bis-(2.ethylhexyl)amine 0.7 Diethyl sulfide MlKible Di-isobutyl carbinol Miscible Di-isobutylene 3.3 <0.6% DMSO soluble in di-isobutylei>e) Disopropyl ether 11 Dimethyl ether 4.4 Dimethyl formamide Miscible Morpholine Naphthalene Neoprene Nitrobenzene Oleic acid Ouricuri wax Oxalic add Palmitic acid Paraffin Paraformaldehyde Miscible 40 Insol. Miscible Misdble 38 100 Insoluble Insoluble Miscible Inso 1 Slightly soluble... 

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