Benzene solution with toluene

Alumina for esterification. A simple and rapid method of esterification which is particularly convenient for working on a scale of 20 mg. to 20 g. is as follows. An alcohol, for example ergosterol, is treated in benzene solution with a slight excess of benzoyl chloride or p-phenylazobenzoyl chloride and 2 equivalents of pyridine. When the reaction is complete, filtration through a small column of alumina (activity II, Woelm E. Merck) gives a solution of the desired ester in pyridine. After evaporation of the benzene, pyridine is removed by addition of toluene and evacuation on the steam bath. 

Naphthalene is a solid near room temperature, but it forms a nearly ideal liquid solution with benzene or with toluene. Show that the mole fraction of naphthalene in a solution that is equilibrated with solid naphthalene (a saturated solution) has the same mole fiaction of naphthalene, whether the solvent is benzene or toluene. 

Solutions of dinitrogen pentoxide have been used in preparative nitrations.Benzene, bromobenzene, and toluene were nitrated rapidly in solutions of the pentoxide in carbon tetrachloride nitrobenzene could not be nitrated under similar conditions, but reacted violently with solid dinitrogen pentoxide. 

Characteristics of the system as nitrating reagents Wibaut, who introduced the competitive method for determining reactivities (his experiments with toluene, benzene and chlorobenzene were performed under heterogeneous conditions and were not successful), pointed out that solutions of nitric acid in acetic anhydride are useful in making comparisons of reactivities because aromatic compounds are soluble in them. ... 

The main product, benzene, is represented by solute (B), and the high boiling aromatics are represented by solute (C) (toluene and xylenes). The analysis of the products they obtained are shown in Figure 12. The material stripped form the top section (section (1)) is seen to contain the alkanes, alkenes and naphthenes and very little benzene. The product stripped from the center section appears to be virtually pure benzene. The product from section (3) contained toluene, the xylenes and thiophen which elutes close to benzene. The thiophen, however, was only eliminated at the expense of some loss of benzene to the lower stripping section. Although the system works well it proved experimentally difficult to set up and maintain under constant operating conditions. The problems arose largely from the need to adjust the pressures that must prevent cross-flow. The system as described would be virtually impossible to operate with a liquid mobile phase. 

A mixture of 2-chloro-A-(2-hydroxyl-l-methyl-2-phenylethyl)benzamide (44) (9.5g, 24.9 mmol) and P2O5 in o-chlorobenzene (1,50 mL) was refluxed overnight. Upon completion, the reaction was cooled to room temperature and then chilled to 0 °C. To the crude reaction mixture, 300 mL of water was cautiously added. The resulting dark solution was washed with toluene (2 x 50 mL). The aqueous layer was cooled to 0 °C and 50% NaOH added to final pH of 11. The resulting mixture was extracted with toluene (4 x 50 mL). The toluene fractions were combined, dried, filtered and concentrated in vacuo. The residue was crystallized from benzene to afford l-(2-chlorophenyl)-3-methylisoquinoline (45) as a white solid (6.68g, 80%). M.P. = 107-108 °C H NMR (CDCI3) S 8.45 (s, IH), 8.11 (d, IH), 7.85 (dt, IH), 7.41-7.68 (bm, 6H), 2.51 (s, 3H). 

A mixture of 50 parts of the distillate, 25.6 parts of 3-bromoethyl acetate, 10.7 parts of potassium carbonate and 400 parts of toluene is stirred at reflux temperature for 16 hours. The mixture is heated with water. The organic layer is separated, washed with water and extracted with dilute hydrochloric acid. The resulting extract is washed with benzene, rendered alkaline and extracted with benzene. The resulting benzene solution is dried over anhydrous potassium carbonate, filtered and concentrated. The residue is dissolved in 300 parts of ethanol and treated with 2.2 equivalents of a 25% solution of anhydrous hydrochloric acid in 2-pro-pa nol. The resulting crystals are recrystallized from 400 parts of ethanol and 10 parts of water. The dihydrochloride of N-( 3-acetoxyethyl)-N -[7-(2 -chloro-10 -phenothiazine)propyl] piperazine melts unsharply at about 200°C to 230°C. 

Griffin and Albaugh [102] describe a procedure whereby the neutral AOS product is converted to the parent acids by cation exchange and then titrated potentiometrically. A dilute aqueous solution of AOS is passed through cationic ion exchange resin in acid form. The acids are eluted with small portions of water and titrated potentiometrically using tetrabutylammonium hydroxide solution in a solvent mixture of 70 30 benzene/methanol. It is probable that the benzene can be replaced with toluene for safety reasons or that ASTM titration solvent (ASTM D664 toluene/propan-2-ol/water) can be used. 

A hypothetical solution that obeys Raoult s law exactly at all concentrations is called an ideal solution. In an ideal solution, the interactions between solute and solvent molecules are the same as the interactions between solvent molecules in the pure state and between solute molecules in the pure state. Consequently, the solute molecules mingle freely with the solvent molecules. That is, in an ideal solution, the enthalpy of solution is zero. Solutes that form nearly ideal solutions are often similar in composition and structure to the solvent molecules. For instance, methylbenzene (toluene), C6H5CH, forms nearly ideal solutions with benzene, C6H6. Real solutions do not obey Raoult s law at all concentrations but the lower the solute concentration, the more closely they resemble ideal solutions. Raoult s law is another example of a limiting law (Section 4.4), which in this case becomes increasingly valid as the concentration of the solute approaches zero. A solution that does not obey Raoult s law at a particular solute concentration is called a nonideal solution. Real solutions are approximately ideal at solute concentrations below about 0.1 M for nonelectrolyte solutions and 0.01 M for electrolyte solutions. The greater departure from ideality in electrolyte solutions arises from the interactions between ions, which occur over a long distance and hence have a pronounced effect. Unless stated otherwise, we shall assume that all the solutions that we meet are ideal. 

Fig. 113.—Comparison of observed entropies of dilution (points and solid lines with results calculated for ASi according to Eq. (28) (broken line). Data for polydimethyl-siloxane, M =3850, in benzene, A (Newing ), obtained from measured activities and calorimetric heats of dilution. Entropies for polystyrene (Bawn et in methyl ethyl ketone,, and in toluene, O, were calculated from the temperature coefficient of the activity. The smoothed results for benzene solutions of rubber, represented by the solid curve without points, were obtained similarly.

Benzene and toluene form complexes with some salts these complexes are often very unstable. With silver perchlorate, benzene gives rise to a complex that leads to very dangerous benzenic solutions. Besides, it detonates when it is ground up. its enthalpy of formation corresponds to -3.4 kJ/g, which makes it dangerous according to the CHETAH criterion (see para 2.3.2). 

To 23 g Na in 350 ml ethanol add 146 g ethyl-oxalate and 171 g 2-nitro-6-CI-toluene and reflux forty minutes. Dilute the red solution with water and steam distill until no more starting material is distilled. The aqueous residue is filtered, acidified with HC1 and filtered to get 102 g 2-nitro-6-CI-phenylpyruvic acid (I) (recrystallize-benzene). Add 81 g (I) in dilute NH4OH to a solution of 560 g FeS04.7H20 and 230 ml concentrated NH4OH and 2 L water and boil five minutes. Filter, wash precipitate with dilute NH4OH, water and acidify filtrate with dilute HCI to get 60 g 4-CI-2-indole-COOH (11) (recrystallize-aqueous ethanol). 9.78 g (II) and 6.7 g CuCN in 35 g quinoline and reflux (about 237°) for twenty hours. Pour the hot solution into a mixture of 25 ml concentrated HCI and ice. Stir and filter wash precipitate with water and extract the filtrate and precipitate three times with ether. Wash the ether with HCI, water and dry, evaporate in vacuum to get 3.6 g 4-CN-indole (recrystallize-water). Or, heat (II) alone at 290° until fusion then heat at 250° for ten minutes until C02 evolution ceases to get 4-CN-indole. For conversion to 4-formyl-indole see HC A 51,1616(1968). 

The only thallium compound to be discussed here is the Tlf,Cl2[Si(CMe3)3]6 cluster 61. This remarkable compound was formed by the reaction of thallium) 111) chloride with NaSi(CMe3)3 [Eq. (28)] and precipitated in the form of black crystals in 21% yield, when a solution in toluene was stored at —25 °C for six months [92], Solutions of 61 in benzene decompose slowly at room temperature by the formation of ClSi(CMe3)3 and a black, not identified precipitate. The structure of 61 consists of two four-membered T13C1 heterocycles, which are connected by one Tl-Tl and two Tl-Cl bonds. A monomeric TI3CI heterocycle was isolated as a byproduct in which one thallium atom was bonded to two Si(CMe3)3 substituents. 

There is a long history of the preparation of explosive solids or oils from interaction of diazonium salts with solutions of various sulfides and related derivatives. Such products have arisen from benzene- and toluene-diazonium salts with hydrogen, ammonium, or sodium sulfides [1,5] 2- or 3-chlorobenzene-, 4-chloro-2-methylbenzene-, 2- or 4-nitrobenzene- or 1- or 2-naphthalene-diazonium solutions with hydrogen sulfide, sodium hydrogen sulfide or sodium mono-, di- or poly-sulfides [l]-[4,7], 4-Bromobenzenediazonium solutions gave with hydrogen sulfide at -5°C a product which exploded under water at 0°C [2], and every addition of a drop of 3-chlorobenzenediazonium solution to sodium disulfide solution... 

Amination (11) and solution carbonation (8) reactions were carried out as described previously. For solid-state carbonations, a benzene solution of poly(styryl)lithium was freeze-dried on the vacuum line followed by introduction of high-purity, gaseous carbon dioxide (Air Products, 99.99% pure). Analysis and characterization of polymeric amines (11) and carboxylic acids (8) were performed as described previously. Benzoyl derivatives of the aminated polystyrenes were prepared in toluene/pyridine (2/1. v/v) mixtures with benzoyl chloride (Aldrich, 99%). 

Pertechnetate can also be reduced by p-thiocresol in acetic acid solution. With an excess of the reducing agent technetium forms a complex compound which readily dissolves in non-polar solvents such as chloroform, toluene or benzene. 

---