Nitrobenzene, preparation sodium compounds

Ha.loisoquinolines, The Sandmeyer reaction is commonly used to prepare chloroisoquinolines from the amino compound. The corresponding hydroxy compounds are also used by treatment with chlorides of phosphoms. The addition of bromine to a slurry of isoquinoline hydrochloride in nitrobenzene gives a 70—80% yield of 4-bromoisoquinoline [1532-97-4J. Heating 1-chloroisoquinoline [19493-44-8] with sodium iodide andhydriodic acid gives 1-iodoisoquinoline [19658-77-6] (179). 

NH3 Naphth2). If sodium is used in place of potassium, the product detonates as crystallisation starts. This is attributed to energetic expulsion of ammonia held endothermically in the growing crystal lattice. The same also occurs with anthracene and sodium, and nitrobenzene and barium. Caution in preparing and using these compounds is urged. 

Direct preparation of azo compounds in good yields is accomplished by treatment of nitro compounds with lithium aluminum hydride [576], with magnesium aluminum hydride [577], with sodium bis(2-methoxy ethoxy)aluminum hydride [575], with silicon in alcoholic alkali [331] or with zinc in strongly alkaline medium [578], Hydrazobenzene was obtained by controlled hydrogenation of nitrobenzene in alkaline medium (yield 80%) [572] and by reduction with sodium bis 2-methoxyethoxy)alumium hydride (yield 37%) [544],... 

The preparation of azobenzene by reduction of nitrobenzene with zinc dust and sodium hydroxide has been well described [60] except that no specific mention is made of the desirability of carrying the reaction out in the presence of air. As a matter of fact, in the older literature, mention is made of blowing air through the filtrate after the reduction has been completed and the insoluble salts have been filtered off [59], This procedure has been recommended more recently also. Actually, air has been drawn through the product solution for as long as 6 hr to oxidize any hydrazo compound which may be present [61]. However, as shown by Blackadder and Hinshelwood [50], we believe that the presence of modest amounts of air toward the end of the reduction cycle should be sufficient for obtaining adequate yields. 

H. L. Wells and H. L. Wheeler (1892) prepared CteSiUm penta-iodide, Csl6, as a black liquid, which solidified at about 73°, by heating caesium tri-iodide with water, or solid iodine with a soln. of caesium iodide. If a cone, alcoholic soln. of the impure solid be treated with two eq. of iodine, and cooled, triclinic black crystals of the penta-iodide are formed with axial ratios a b c=0 9890 1 042765. H. M. Dawson and E. E. Goodson isolated a compound of sodium penta-iodide, Nal5.2C6H5N02, from a nitrobenzene soln. of iodine and sodium iodide. 

There is, unfortunately, no obvious correlation between the impact sensitivity of a compound, its thermal behavior, and its structure. Thus, most polynitro arenes can explode on mechanical shock or rapid heating [96], but the shock sensitivity and thermal stability varies widely. TNT, for instance, is rather insensitive toward mechanical shocks or heating, and even pentanitrotoluene and hexanitrobenzene have been prepared, and their melting points (240 °C and 260 °C, respectively) could be determined [97]. The potassium salt of the radical anion of nitrobenzene, on the other hand, is highly shock sensitive, and detonates on simple agitation [92], Similarly, whereas nitromethane can be handled safely the dry sodium salt of deprotonated nitromethane is potentially explosive [98]. 

The cupric oxidation of lignins is optimally performed by heating a mixture of lignin preparation, cupric oxide, and sodium hydroxide m an approximate weight ratio of 1 6 2 9 m an autoclave at 170°C for 2-5h, the concentration of sodium hydroxide being 1 5-2 M (Pearl and Beyer 1950, Pepper et al 1967) In the laboratory, cupric oxide oxidation of lignins is usually conducted according to the procedure of Pepper and co-workers (1967) The constituents of the oxidation mixture are qualitatively and quantitatively determined as described for the compounds m nitrobenzene oxidation mixtures... 

The compound is prepared technically by heating m-nitrobenzene with a strong aqueous solution of sodium polysulphide prepared by dissolving sulphur in a solution of sodium sulphide. 

Dapsone has been prepared by a number of procedures (1,48). One procedure employs the reaction of l-chloro-4-nitrobenzene with excess sodium sulfide to give the 4-amino-4 -nitrodiphenyl sulfide. This compound, after acetylation of the amino group, is oxidized with H2O2 to the sulfone. The nitro group is then reduced to amino, and hydrolysis of the acetyl gives the product. 

He also concluded that at such concentrations the ions in the vicinity of the electrode are exhausted by reduction and that the current intensity depends mostly on the number of metal ions transported into this space by diffusion. He also pointed out that the position of the wave on the potential axis is characteristic of the reduced species and can be used for qualitative analysis. From occurrence of waves at -0.4 and -0.6 V in solutions prepared from metallic zinc, it was possible to conclude the presence of two impurities, attributed tentatively to indium and gallium. M. Shikata at the same meeting reported (11) the possibility of carrying out the reduction at the D.M.E. in a nonaqueous system - in sodium ethoxide. In the following year the Japanese chemist reported also the first reduction of an organic compound, nitrobenzene (12,13). 

Also obtained (by-product) by diazotization of 2-amino-5-nitrobenzophenone (4%). The 2-nitrofluorenone was the major compound obtained (75%) [539]. Also obtained (poor yield) by Fries rearrangement of p-nih Ophenyl benzoate with aluminium chloride in nitrobenzene at 170° for 1 h (4%) [540]. Preparation from 2-nitrothioxanthen-9-one 10,10-dioxide (SM) by a three-step synthesis SM by refluxing in a solution of 2% sodium hydroxide in dioxane/ water mixture (65 35) for 2 h, gave the 2-(2-hydroxy-5-nitrobenzoyl)phenyl-sulfmic acid (89%). The former by reaction with mercuric chloride in refluxing aqueous acetic acid for 4 h led to the 2-chloromercuri-2 -hydroxy-5 -nitro-benzophenone (82%). Removal of the chloromercury group was achieved with concentrated hydrochloric acid in refluxing ethanol for 2 h (84%) [62]. 

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