Acetonitrile nitromethane mixture

Fig. 3. 7Li NMR shift measured for 0.05 M LiC104 in acetonitrile— nitromethane solvent mixtures at 25°C (93).

Methylation of 3-nitro-2,5-diphenyl-1,4-dithiin using a mixture of methyl iodide and silver tetrafluoroborate in methylene chloride/acetonitrile/nitromethane gave a mixture of two products in the ratio of 3 1. The major product was shown to be l-methyl-6-nitro-2,5-diphenyl-l,4-dithiinium tetrafluoroborate and the minor component to be 3-(dimethylsulphonio)-5-nitro-2,4-diphenylthiophene tetrafluoroborate. 

Alkylation of N-unsubstituted tetrazoles with alcohols can be performed under a variety of conditions. Alcohols that readily generate carbocations in the presence of acidic catalysts react with N-unsubstituted tetrazoles yielding mixtures of N1- and N2-alkylated products. The reaction can be carried out in a neutral organic solvent (chloroform, dichloromethane, acetonitrile, nitromethane) in the presence of catalytic amounts of sulfuric, />-toluenesulfonic, or... 

Another set of papers is due to Mancini and coworkers111-113. In mixtures of acetonitrile or nitromethane with ethyl acetate, 2-butanone, acetone, DMF and DMSO, the differences between the results for 2 and 5 were much smaller (<0.04) than noted above over the entire composition ranges, hence their averaged n values appear to be measures of the polarity/polarizability of the mixtures rather than probe-dependent quantities. The same appears to be the case for the EPD/HBA properties measured by the 2/1 and 8/5 probe pairs of mixtures of acetonitrile with ethyl acetate, DMF and DMSO, but not for acetonitrile-rich mixtures with DMF or DMSO, where the differences between the two probe pairs are considerable111. Mixtures of aprotic polar solvents with chloroform showed discrepancies of the results for 2 and 5 of up to 0.15 units, whereas for such mixtures with dichloromethane the differences were smaller, up to 0.05 units in ji. The 2/1 and 8/5 probe pairs for EPD/HBA properties of these mixtures showed differences for both chloroform and dichloromethane mixed with ethyl acetate, acetonitrile and DMSO, precluding the estimation of reliable ft values111. The results with HBD solvent components were interpreted in terms of specific interactions with the probes113. 

Sumithion (Bayer 41831) (see also Petschik [72]). Blinn [9] has midertaken the identification of oxidation products of phorate (in the Thimet mixture) in plant residues he chromatographed on silica gel G layers, using chloroform-methanol (98.2 + 1.8) and toluene-acetonitrile-nitromethane (45 + 40 + 15)-... 

Crown-6 [17455-13-9] M 264.3, m 37-39 . Recrystd from acetonitrile and vacuum dried. Purified by pptn of 18-crown-6/nitromethane 1 2 complex with Et20/nitromethane (10 1 mixture). The complex is decomposed in vacuum and distilled under reduced pressure. Also recrystd from acetonitrile and vacuum dried. 

Figure 7. Infrared spectrum of pyrethrin I Isolated after dual partition chromatography First partition column. Celite-acetonitrile-hexane Second partition column. Silicic acid-nitromethane-hexane (with 5% acetone). Corresponds to peak 3 of gas chromatographic separation of pyrethrum mixture...

Since the initially formed enol ester rearranges slowly to an imide,3 the yield depends on the rate at which the isoxazolium salt reacts, and that rate is increased by vigorous stirring. The reaction time for the activation step is approximately 8 minutes in nitromethane at 25° and approximately 1 hour in acetonitrile at 0°. In reactions performed with acetonitrile as the solvent, the checkers did not obtain complete solution. The reaction flask should be kept in a water bath to minimize heat transfer from the magnetic stirrer to the reaction mixture. 

The triethylamine salts of peptide acids are often relatively insoluble in acetonitrile or nitromethane therefore, the supersaturated solution formed on mixing the amine and the acid should be added to this reaction mixture immediately, before crystallization occurs. If crystallization does occur, the mixture should be heated to dissolve the salt, cooled rapidly, and added to the reaction mixture immediately. If it is impossible to obtain a solution of the salt, the peptide acid and then the triethylamine solution may be added separately to the reaction mixture with only a small sacrifice in yield. 

Dilute solutions of dinitrogen pentoxide in carbon tetrachloride, nitromethane, acetonitrile, chloroform, and mixtures of the first two solvents give approximately second-order kinetics, viz. 

Relative rates of alkylation of toluene and benzene using a mixture of nitro-sonium hexafluorophosphate, nitromethane (or acetonitrile) and aliphatic amine as the alkylations agent have been determined at 25 °C as follows360 1.5 (ethyl-amine), 2.5 (i-propylamine) and 3.5 (benzylamine) nothing more as yet is known about the kinetics of alkylation with these new alkylating reagents. 

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. 

On application of the NMR method mentioned above for the solvent mixture consisting of acetonitrile (DAT —14.1) and nitromethane (DN = 2.7), it was found that also in this case the Li+ ion is coordinated bv four acetonitrile molecules (Fig. 3). 

Conductance studies of Li+ and Na+ in Acetonitrile and Nitromethane binary mixtures at 298.15 K... 

Through selective complexation with nitromethane, dimethyl carbonate and dimethyl oxalate, it was possible to isolate [18]crown-6 in 98 % purity from a crude reaction mixture 14a). Although the acetonitrile complex with [18]crown-6 has been known for some time, the structure was determined only recently because of rapid crystal deterioration 14). 

The effect of solvent on these types of reaction is particularly well illustrated by the case of 2,4-dimethylthiazole in dimethylformamide, 18 is obtained in acetonitrile or dimethyl sulfoxide, a mixture of 18 and 23 results and using tetrahydrofuran, dichloromethane, or nitromethane, essentially only 23 is produced641,644 Adduct 23 could be formed as outlined in Scheme 15, and similar compounds are obtained from 2-ethylthiazole, suitably substituted benzothiazoles641 and some other heterocycles. 

Nitromethane shows the simplest residue curve map with one unstable curved separatrix dividing the triangle in two basic distillation regions. Methanol and acetonitrile give rise two binary azeotropic mixtures and three distillation regions that are bounded by two unstable curved separatrices. Water shows the most complicated residue curve maps, due to the presence of a ternary azeotrope and a miscibility gap with both the n-hexane and the ethyl acetate component. In all four cases, the heteroazeotrope (binary or ternary) has the lowest boiling temperature of the system. As it can be seen in Table 3, all entrainers except water provide the n-hexane-rich phase Zw as distillate product with a purity better than 0.91. Water is not a desirable entrainer because of the existence of ternary azeotrope whose n-hexane-rich phase has a water purity much lower (0.70). Considering in Table 3 the split... 

The intermediary formation of a "monometaphos-phate (cf. (4)) in a type A reaction is indicated by the hydrolysis of Py P02Cl. The reaction of la with equimolar amounts of water in nitromethane yields a polyphosphate mixture, whereas in acetonitrile cycli-zation ot the [P03] - anions to trimetaphosphate is observed. The reaction can be formulated as an S.,1(P) (elimination - addition) as follows N... 

Chloro-7-bromo-l,2,3,5-tetrahydroimidazo[2,l-b]quinazolin-2-one was produced next way to a solution of 1.30 g (8 mmole) of anhydrous ferric chloride in 30 ml of nitromethane was added 1.30 g (5 mmole) of solid 6-chloro-l,2,3,5-tetrahydroimidazo[2,l-b]quinazolin-2-one and 0.80 g (5 mmole) of bromine. The system was stoppered, warmed to 50°C in an oil bath overnight, cooled to room temperature and the solvent removed in vacuo. The resulting solid was suspended in water (50 ml), the mixture was made basic (pH = 10) with sodium bicarbonate and stirred at home temperature for 20 min. The solid was filtered under suction, washed with water, then isopropyl alcohol and dried yielding 1.19 g of 6-chloro-7-bromo-l,2,3,5-tetrahydroimidazo[2,l-b]quinazolin-2-one (78% yield). Purification was effected by formation of the hydrochloride salt (mp 275°C) from acetonitrile. 

Readion of anisole (1) with acetic anhydride was chosen as a model, and ytterbium trifluoromethanesulfonate (ytterbium triflate, Yb(OTf)3) was the first RE(OTf)3 representative used. Several reaction conditions were examined the results are summarized in Table 1. When acetic anhydride, acetonitrile, or nitromethane was used as a solvent (entries 4—10), the reaction mixture became homogeneous and the acylation reaction proceeded smoothly. Nitromethane gave the highest yield of4-methoxyaceto-phenone (2) (entries 7-10). On the other hand, in carbon disulfide, dichloroethane, or nitrobenzene (entries 1-3), the reaction mixture was heterogeneous and the yield of 2 was low. It was noted that the acylation proceeded quantitatively when a catalytic amount of Yb(OTf)3 was used (0.2equiv., entry 9). Even when 0.05 equiv. of the catalyst was employed, 2 was obtained in 79 % yield (entry 10). 

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