Tetrachloroethane-Nitrobenzene

I RIEDEL-CRAFTS ACYLATION Nitro-ethane. Tetrachloroethane-nitrobenzene. Trichloroacetyl chloride. 

Colorless monoclinic prisms From glacial acetic acid. Turns pink easily. Unstable in air. Hydrolyzed by water with the Formation of brown lead dioxide and acetic acid. Avoid contact with skin, dj7 2.228. mp 175-180°. Sol in hot glacial acetic acid, benzene, chloroform, tetrachloroethane, nitrobenzene. Dissolves in coned halogen acids with the formation of haloplumbic acids, H,PbX6. The dry material can be stored in sealed, evacuated ampuls. 

In the first of a series of new reactions, Meerwein heated JV-phenylbenz-imidoyl chloride (56) with acetonitrile and aluminum chloride to obtain 4-methyl-2-phenylquinazoline (see 1). He postulated that the nitrilium salt (57) (not isolated) was the intermediate. Aromatic nitriles could also be used. The imidoyl chloride could be replaced by a mixture of benzanilide and thionyl chloride other Lewis acids could replace the aluminum chloride. The solvent could be tetrachloroethane, nitrobenzene, or an excess of the nitrile. Best reaction temperatures ranged from 90° to 160°C and yields were usually excellent. Imidate esters, e.g., PhNC(Ph)OEt, could replace the imidoyl chloride.41... 

As already mentioned in Chapter 6, Section 4, appropriate solvents for conducting Friedel—Crafts crosslinking reaction of polystyrene are EDC, tetrachloroethane, nitrobenzene, and cyclohexane (at an elevated temperature). While the products prepared in the first two solvents are identical in aU their swelling behavior, the character of swelling of materials obtained in nitrobenzene is different. 

Polyethylene terephthalate Styragel columns Tetrachloroethane/nitrobenzene (99.5 0.5) Gel permeation chron room temperature cor in nitrobenzene at 18( with boiling TCE... 

The Mark-Houwink constants for poly(ethylene terephthalate) (PET) and its copolymers with isophthalate in tetrachloroethane/nitrobenzene (95 5, v/v)... 

Tetrachloroethane is a good solvent for many compounds which dissolve only slightly in the common solvents it is, however, inferior in solvent power to nitrobenzene, but, on the other hand, it does not possess oxidising properties at the boiling point. 

Pyrolysis Thermal decomposition of 1,1,1,2-tetrachloroethane produces tetrachloroethylene (by disproportionation), hydrogen chloride, and trichloroethylene via dehydrochlorination (111). The yield of the latter is increased in the presence of ferric chloride (112). Other catalytic materials include FeCl —KCl mixture (113), AlCl (6), the complex of AlCl with nitrobenzene (114), activated alumina (3), Ca(OH)2 (115,116), and NaCl (94). 

The solvents most commonly employed are water, ethyl and methyl alcohol, ether, benzene, petroleum ether, acetone, glacial acetic acid also two or three solvents may be mixed to get the desired effect as described later. If you still cannot dissolve the compound, try some of these chloroform, carbon disulfide, carbon tetrachloride, ethyl acetate, pyridine, hydrochloric acid, sulfuric acid (acids are usually diluted first), nitrobenzene, aniline, phenol, dioxan, ethylene dichloride, di, tri, tetrachloroethylene, tetrachloroethane, dichloroethyl ether, cyclohexane, cyclohexanol, tetralin, decalin, triacetin, ethylene glycol and its esters and ethers, butyl alcohol, diacetone alcohol, ethyl lactate, isopropyl ether, etc. 

Poly(2,6-dimethylphenylene ether) is amorphous and has a glass transition temperature of about 170 °C. It is soluble in chlorinated hydrocarbons such as chloroform, carbon tetrachloride, as well as tetrachloroethane,and also in nitrobenzene and toluene. 

The usual range of solvents associated with Friedel-Crafts reactions is available carbon disulfide and nitrobenzene have found frequent use. The choice of solvent may influence the extent of cyclization. Thus, in ether, 1,2,3,5-tetramethoxybenzene yielded the uncyclized product with 3,3-dimethylacryloyl chloride, whereas in a mixture of ether and tetrachloroethane the major product was the chromanone. This example is also of interest since ring closure could involve either the 2- or 6-methoxy group. In fact, the formation of the 5,6,7-trimethoxy isomer was not observed. The identity of the product was established by conventional 14C labelling (60BSB593). 

The most common solvents are benzene and carbon disulfide. Others such as petroleum ether and sj/m-tetrachloroethane also have been employed successfully. Nitrobenzene has served as a unique solvent in conjunction with aluminum chloride, since a complex is formed reducing the activity of the catalyst. 

Cyclization of Anhydrides. Instead of the acid chloride, an intramolecular anhydride of the type LXXIX may be used for cyclization by the Friedel-Crafts reaction (Table VII, examples marked by h ). This resembles the intermolecular acylation with succinic anhydride, and a similar procedure is generally followed. The product of ring closure is a keto acid LXXX. Nitrobenzene 9i 6,1120 is a generally effective solvent for the reaction sym-tetrachloroethane also may be used.121... 

In the case of Friedel-Crafts reactions, mild conditions are essential, since binaphthyls are formed under vigorous conditions. Reaction with acetyl chloride in tetrachloroethane in the presence of aluminium chloride gives 1-acetylnaphthalene (Scheme 12.5), although in nitrobenzene the 2-acetyl derivative 11 is the major product. Attack at the less hindered 2-position is preferred in the latter case because of the larger size of the solvated acylating species. 

Succinoylation, The succinoylation of anisole with succinic anhydride to give 3-(/7-melhoxybenzoyl)propionic acid is carried out most conveniently in a mixture of tetrachloroethane and nitrobenzene (4 1). 

The compound consists of colorless crystals which melt at 35.7°. A supercooled melt shows a refractive index = 1.5313. The compound is very sensitive toward hydrolysis. It is readily soluble in benzene, nitrobenzene, and tetrachloroethane. 

Di-j3-naphthylamine and arsenious chloride in sz/wi.-tetrachloroethane condense after ninety minutes boiling, the product being filtered and recrystallised from nitrobenzene. It separates in yellow needles, M.pt. 355° C., with decomposition. Yield, 55 per cent. 

Naphthalene can be acetylated by acetyl chloride in the presence of aluminum chloride. The orientation of substitution is determined by the particular solvent used predominantly alpha in carbon disulfide or solvents like tetrachloroethane, predominantly beta in nitrobenzene. (The effect of nitrobenzene has been attributed to its forming a complex with the acid chloride and aluminum chloride which, because of its bulkiness, attacks the roomier beta position.)... 

The polymers are soluble in hot solvents such as 1,1,2,2-tetrachloroethane, o-dichlorobenzene, trichlorobenzene, and nitrobenzene. Polymers having an odd number of methylene units in the spacer have a higher solubility than those having even-numbered spacers. The solubility also tends to increase with increasing length of... 

Naphthalene and phthalic anhydride in benzene, o-dichlorobenzene, or tetrachloroethane reacted with A1C1S -> mixture of 60-70% a- and 30-40% / -naphthoyl-o-benzoic acid (Y 91-93%) with HB02 and H2S04 warmed at 60° for 6 hrs. 1,2-benzanthraquinone (Y 84%). —In nitrobenzene and CS2, the Friedel-Crafta reaction with A1C13 also gives a mixture of isomers, but in lower yields.—The ring closure with A1C13 is not uniform. (A. Eitel and R. Fialla, M. 79, 112 (1948) cf. Synth. Meth. 2, 746 5, 604.)... 

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