Anhydrous acetonitrile

Nonselective attacks at carbon bonded with nitro group and carbon bonded with azoxy group were observed in reactions of 239 with bases in anhydrous acetonitrile (Scheme 161) (98CEJ1023). Reaction of 4,4 -dinitroazoxyfurazan occurred in a similar way (000HAC48). 

C. 3-Methyl-2,i-heptanedione. A dry, 500-ml., three-necked, round-bottomed flask equipped with a magnetic stirring bar, a pressureequalizing dropping funnel, a thermometer, and a condenser fitted with a nitrogen-irdet tube is charged with 17.8 g. (0.20 mole) of anhydrous lithium bromide (Note 21). Under- a nitrogen atmosphere, 34.8 g. (0.20 mole) Of -(2-oxobut-3-yl) butanethioate dissolved in 120 ml. of anhydrous acetonitrile (Note 22) is added to the flask. 

The absence of water in the lithium bromide is of great importance. Traces of wrater lower the yield of product by 10-20%. LiBr-2 H20 (purchased from E. Merck Company, Inc., Darmstadt or City Chemical Corporation) was dissolved three times in anhydrous acetonitrile-benzene (1 1), and the solvents removed each time on a rotary evaporator. The lithium bromide was dried under high vacuum at 100° for 1 hour, ground to a fine powder with a mortar and pestle while still warm, and again dried at 100°, as above, for 3 hours. 

Positive halogen reagents can cyclize y- and 8-hydroxyalkenes to tetrahydro-furan and tetrahydropyran derivatives, respectively.85 Iodocyclization of homoal-lylic alcohols generates 3-iodotetrahydrofiirans when conducted in anhydrous acetonitrile.86 The reactions are stereospecific, with the /(-alcohols generating the irons and the Z-isomer the cis product. These are endo-5 cyclizations, which are preferred to exo-4 reactions. 

Amino acids activated at the amino group by a benzotriazolide moiety react with amino acids under elimination of benzotriazole and C02 to give peptides. Reaction is achieved by warming up equimolar amounts of the components in anhydrous acetonitrile or aqueous acetone.[45] The benzotriazolylcarbonylamino acids are prepared from benzo-triazolyl-1-carboxylic acid chloride and amino acids.[46]... 

A large number of reagents are available for the preparation of nitro PAHs. These include fuming nitric acid in acetic acid (20) or acetic anhydride (13), sodium nitrate in trifluoroacetic acid (21) or trifluoroacetic acid and acetic anhydride (17), dinitrogen tetroxide in carbon tetrachloride (22), sodium nitrate in trimethyl phosphate and phosphorus pentoxide (23), and nitronium tetrafluoroborate in anhydrous acetonitrile (24). Alternative approaches must be used to synthesize nitro PAHs substituted at positions other than the most reactive carbon. For instance,... 

Fluoride ion is effective in promoting the reduction of aldehydes by organosil-icon hydrides (Eq. 161). The source of fluoride ion is important to the efficiency of reduction. Triethylsilane reduces benzaldehyde to triethylbenzyloxysilane in 36% yield within 10-12 hours in anhydrous acetonitrile solvent at room temperature when tetraethylammonium fluoride (TEAF) is used as the fluoride ion source and in 96% yield when cesium fluoride is used.83 The carbonyl functions of both p-anisaldehyde and cinnamaldehyde are reduced under similar conditions. Potassium bromide or chloride, or tetramethylammonium bromide or chloride are not effective at promoting similar behavior under these reaction conditions.83 Moderate yields of alcohols are obtained by the KF-catalyzed PMHS, (EtO SiH, or Me(EtO)2SiH reduction of aldehydes.80,83,79... 

Characteristically, for these reactions in anhydrous acetonitrile, at least one additional reaction step is also observed. Whereas the initial solvent exchange step is fast in each case and shows a first-order depen-... 

Unsymmetrical 3,4-dihalo-l,2,5-thiadiazoles 118 and 119 were prepared from 3-amino-4-chloro-l,2,5-thiadiazole 117 via a Sandmeyer-like reaction involving successively tert-butyl nitrite and either copper bromide or copper iodide in anhydrous acetonitrile (Scheme 17) <2003H(60)29>. The bromo and iodo thiadiazoles 118 and 119 undergo selective Stille and Suzuki C-C coupling chemistry (see Section 5.09.7.6). 

Iodocyclization of the olefinic tetrazole 5-but-3-enyl-l//-tetrazole 79 using Nal ICO ( and I2 in anhydrous acetonitrile at 0 °C under argon atmosphere in the dark affords a 72% isolated yield of a 1 1 mixture of 5-iodomethyl-6,7-dihydro-tetrazolo[l,5-zr] pyrrole 80 and 6-iodo-5,6,7,8-tctrahydro-tetrazolo[1,5-tf]pyridinc 81 (Equation 5) <2003T6759>. 

B. 2,2-(Trimethylenedithio)cyclohexanone. A solution of 3.02 g. (0.02 mole) of freshly distilled 1-pyrrolidinocyclohexene, 8.32 g. (0.02 mole) of trimethylene dithiotosylate4 (Note 2), and 5 ml. of triethylamine (Note 3) in 40 ml. of anhydrous acetonitrile (Note 4), is refluxed for 12 hours in a 100-ml., round-bottom flask under a nitrogen atmosphere. The solvent is removed under reduced pressure on a rotary evaporator, and the residue is treated with 100 ml. of aqueous 0.1 N hydrochloric acid for 30 minutes at 50° (Note 5). The mixture is cooled to ambient temperature and extracted with three 50-ml. portions of ether. The combined ether extracts are washed with aqueous 10% potassium bicarbonate solution (Note 6) until the aqueous layer remains basic to litmus, and then with saturated sodium chloride solution. The ethereal solution is dried over anhydrous sodium sulfate, filtered, and concentrated on a rotary evaporator. The resulting oily residue is diluted with 1 ml. of benzene and then with 3 ml. of cyclohexane. The solution is poured into a chromatographic column (13 x 2.5 cm.), prepared with 50 g. of alumina (Note 7) and a 3 1 mixture of cyclohexane and benzene. With this solvent system, the desired product moves with the solvent front, and the first 250 ml. of eluent contains 95% of the total product. Elution with a further 175 ml. of solvent removes the remainder. The combined fractions are evaporated, and the pale yellow, oily residue crystallizes readily on standing. Recrystallization of this material from pentane gives 1.82 g. of white crystalline 2,2-(trimethylenedithio)cyclo-hexanone, m.p. 52-55° (45% yield) (Note 8). 

Under nominally aprotic conditions, 1,2-protonation dominates in naphthalene. Reduction of naphthalene in anhydrous acetonitrile containing tetraethylammo-nium p-toluenesulfonate yields 1,2-di-hydronaphthalene, which is subsequently... 

In practice, the synthesis was carried out as outlined in the retrosynthetic Scheme 13.2.8. The Diels-Alder reaction between butadiene and (+)-(/ )-5-methyl-2-cyclohexenone (31), in the presence of SnCl in anhydrous acetonitrile solution at... 

There are a few reports of poly(naphthalene) thin films. Yoshino and co-workers. used electrochemical polymerization to obtain poly(2,6-naphthalene) film from a solution of naphthalene and nitrobenzene with a composite electrolyte of copper(II) chloride and lithium hexafluoroarsenate. Zotti and co-workers prepared poly( 1,4-naphthalene) film by anionic coupling of naphthalene on. platinum or glassy carbon electrodes with tetrabutylammonium tetrafluoroborate as an electrolyte in anhydrous acetonitrile and 1,2-dichloroethane. Recently, Hara and Toshima prepared a purple-colored poly( 1,4-naphthalene) film by electrochemical polymerization of naphthalene using a mixed electrolyte of aluminum chloride and cuprous chloride. Although the film was contaminated with the electrolyte, the polymer had very high thermal stability (decomposition temperature of 546°C). The only catalyst-free poly(naphthalene) which utilized a unique chemistry, Bergman s cycloaromatization, was obtained by Tour and co-workers recently (vide infra). 

Relaxivities were measured either as a function of the applied field or in titration experiments at 20 MHz in anhydrous acetonitrile solutions of Gd(C104)3, i.e., in the simplest possible conditions with no competition from water or coordinating anions for the complexation of the metal ions. 

Fig. 10. NMRD curves of free Gd (O) and its complexes with calix[4]arenes2(0) (at the maximum of the relaxivity titration curve), 3 ( ) (at the maximum of the relaxivity titration curve), 4 (A) (ligand to metal ratio = 2) in anhydrous acetonitrile at 25° C (63,66,67).

Oxidation of acridine in anhydrous acetonitrile leads to a dimer 65 formed by reaction of the nitrogen in one molecule of the substrate with the point of highest positive charge density in a radical-cation [208]. Anodic oxidation of neat pyridine... 

Nitroxyl mediated electro-oxidation of primary amines also leads to formation of the imine and the further oxidation to the nitrile. In anhydrous acetonitrile containing 2,6-lutidine as a base, the nitrile is formed. In aqueous acetonitrile, hydrolysis of the imine intermediate is fast and good yields of the aldehyde result... 

Sulfamic acid (+H3NS03 ) has been proved to be an efficient and green catalyst for liquid Beckmann rearrangement of ketoxime in anhydrous acetonitrile. Due to its intrinsic zwitterionic property, the use of a base for the neutralization is avoided and wastes can be reduced. 

Weight gain data and oxidation-reduction titers (Table II) for the niobium (V) chloride and bromide reaction products both indicated the reduction of niobium (V) to niobium (IV). The niobium (IV) adducts were separated by washing the crude reaction mixtures with anhydrous acetonitrile. This solvent removed the various organic products of the initial reaction plus any unreduced niobium compounds. Analysis of the washed products gave ratios of Nb X py of 1 4 2 and agreed with analyses for samples of NbCl py2 and NbBr4 py2 which... 

The results of the polymerization experiments are shown in Table 1.6. Besides the facts discussed, it can be seen that triphenyl phosphite, propylamine, and tributylphosphine effectively inhibit the polymerization reaction. In contrast, benzonitrile, triphenyl-arsine, anhydrous acetonitrile, thiophene, and furan accelerate the reaction (25). 

R)-(+)-2-Hydroxy-1,2,2-triphenylethyl acetate [(R)-HYTRA], To a mechanically stirred solution of (R)-(+)-1,1,2-triphenyl-1,2-ethanediol (35.0 g. 0.121 mol, Note 1) and acetic anhydride (17.1 mL, 0.181 mol, 1.5 eq, Note 2) in anhydrous acetonitrile (500 mL, Note 3) at room temperature under nitrogen is added a solution of scandium(lll) trifluoromethanesulfonate (1.23 g, 2.5 mmol, 2 mol%, Note 4) in anhydrous acetonitrile (125 mL) over approximately 35 min (Note 5). After about 8 min a white precipitate begins to appear, and the resulting mixture is stirred at room temperature under nitrogen for a total of 3 hr. The solid is filtered, washed with acetonitrile (2 x 25 mL), and dried under vacuum at 40°C overnight to afford (R)-(+)-2-hydroxy-1,2,2-triphenylethyl acetate (35.42 g, 0.107 mol, 88%) as a white solid (Note 6). 

Anhydrous acetonitrile was obtained from Aldrich Chemical Company, Inc. in a Sure/Seal bottle and used as received. 

The heats of solution of lithium perchlorate in aqueous acetonitrile were measured at concentrations between 0.01 and 0.1m. The concentration dependence was small compared with the experimental scatter of about 0.1-0.2 kcal mole-1. AHs values are given in Table II. The heats of solution in anhydrous acetonitrile were corrected to infinite dilution using measured heats of dilution (6), and the corrected values were averaged. The heats of dilution were measured for lithium perchlorate in the mixed solvent containing 90% MeCN. 

Heats of solution for lithium perchlorate in pure water have been reported previously (8). The heats of transfer to the aqueous mixtures and anhydrous acetonitrile are given in Table IV and Figure 2. 

Replacement of the B—OH group with formation of boron-carbon bonds is effected by esterification with butyl alcohol or trimethylsilylation with bis(trimethylsilyl)acetamide (BSA) in anhydrous acetonitrile and subsequent action of organolithium compounds or Grignard reagents on these ethers (Scheme 56). 4,5-Borazarofuro[2,3-c]pyridine itself (256) has been obtained by reduction of (252) as colorless, moisture-sensitive crystals with m.p. 80-85 °C. 

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