Amines potassium nitrite

Fischer polypeptide synthesis org chem A synthesis of peptides in which a-amino acids or those peptides with a free amino group react with acid halides of a-haloacids, followed by amination with ammonia. fish-ar pal-e pep,tTd. sin tha sas ) Fischer projection orgchem) A method for representing the spatial arrangement of groups around chiral carbon atoms the four bonds to the chiral carbon are represented by a cross, with the assumption that the horizontal bonds project toward the viewer and the vertical bonds away from the viewer fish-ar pra.jek-shon) Fischer s salt See cobalt potassium nitrite. fish-3rz solt)... 

A general method of replacement of the primary aromatic amino group by hydrogen is reduction of aromatic diazonium salts, prepared by diazotization, typically by treatment of the primary amine or its salts with sodium or potassium nitrite in strongly acidic aqueous media. Conversion to the diazonium salts may also be accomplished in nonaqueous media using acetic acid, or using alkyl nitrites (equation 86). Most diazonium salts decompose at temperatures above 0-5 C. Only certain salts such as naphthalene-1,5-sulfonates,tetrafluoroborates ° ° and hexafluorophosphates ° ° are stable at room temperature. 

If the mercuric nitrate solution contains an excess of potassium nitrite and 1 per cent, nitric acid and acetylene be passed into the cold mixture, mtritoHliynercuracetaldehycU is precipitated as a bright yellow powder. It is explosive, and is proved to be a nitrite by its behaviour towards a-naphthy]amine in the presence of acetic and hydrochloric aeids. ... 

AMMONIUM SULPHATE (7783-20-2) H8N2O4S Noncombustible solid. Aqueous solution is a strong acid. Violent reaction with fused potassium chlorate potassium nitrite. Reacts with caustics, forming ammonia. Hot material reacts with nitrates, nitrites, chlorates. Incompatible with strong oxidizers sulfuric acid aliphatic amines alkanolamines, amides, organic anhydrides isocyanates, vinyl acetate aUcylene oxides epichlorohydrin. Mixture with sodium hypochlorite forms nitrogen trichloride, an unstable explosive material. Attacks metals in the presence of moisture. 

POTASSIUM NITRITE (7758-09-0) Noncombustible, but many chemical reactions can cause fire and explosions. A powerful oxidizer. Reacts with acids, acid fumes, producing nitrous fumes. Violent reaction with many substances, including reducing agents, alcohols, ammonium salts, amines, boron, combustible materials, ethers, finely divided metals, organic substances, nitric acid, potassium, sulfuric acid. Incompatible with ammonium sulfate, barium sulfide, potassium amide. Decomposes or may explode in elevated temperatures. 

In some cases, amines can be converted to diazo compounds by treatment with potassium nitrite or nitrous acid. The first aliphatic diazo compound known was ethyl diazoacetate (304), prepared by Curtius in 1883. 41 Treatment of ethyl glycinate hydrochloride (303) with potassium nitrite (KNO2) gave 304. This technique is most useful when an electron withdrawing group is adjacent to the amino group. 

The experimental conditions necessary for the preparation of a solution of a diazonium salt, diazotisation of a primary amine, are as follows. The amine is dissolved in a suitable volume of water containing 2 5-3 equivalents of hydrochloric acid (or of sulphuric acid) by the application of heat if necessary, and the solution is cooled in ice when the amine hydrochloride (or sulphate) usually crystallises. The temperature is maintained at 0-5°, an aqueous solution of sodium nitrite is added portion-wise until, after allowing 3-4 minutes for reaction, the solution gives an immediate positive test for excess of nitrous acid with an external indicator—moist potassium iodide - starch paper f ... 

The benzodiazepinone 26 condenses with 3-melhylbulyl nitrite (isopentyl nitrite) in the presence of potassium lerl-butoxide to give the oxime 27, which is converted into the amine 28 by catalytic hydrogenation.227... 

Nitroso-/3-naphthol has been made by the action of hydroxyl-amine hydrochloride on /3-naphtho-quinonc-chlorimide 1 by the action of sulfuric acid upon a solution of potassium or sodium nitrite and the sodium salt of /3-naphthol 2 by the action of sodium nitrite upon an alcoholic solution of zinc chloride and /3-naphthol 3 by the action of sodium nitrite upon /3-naphthol suspended in zinc sulfate solution 4 by the action of nitrous acid on /3-dinaphthol methane 6 and by the action of nitrosyl sulfate upon the sodium salt of /3-naphthol.6... 

The amine (0.1 mole) is dissolved in a buffered (pH 4-5) solution of 500 ml of 60 % aqueous acetic acid and 68 gm of sodium acetate. The reaction mixture is warmed to 90°C. Then 69 gm (1.0 mole) of sodium nitrite dissolved in 100 ml of water is added dropwise over a 45 min period while heating at 90°C is continued. After the addition, the reaction mixture is heated for 2 hr, cooled, poured into 200 ml of cold water, and extracted three times with 200 ml portions of ether. The ether was washed with 10 % potassium carbonate solution until basic, then with saturated sodium chloride solution, dried, stripped, and distilled to obtain the products shown in the table. 

The sensor did not respond to volatile compounds such as acetic acid, ethyl alcohol, and amines (diethylamine, propylamine, and butylamine) or to nonvolatile nutrients such as glucose, amino acids, and metal ions (potassium and sodium ions). Therefore, the selectivity of this microbial sensor was satisfactory in the presence of these different substances. The current output of the sensor was almost constant for more than 21 days and 400 assays. The microbial sensor can be used to assay sodium nitrite for a long period. In the same experiments the concentration of sodium nitrite was determined by both the sensor proposed and the conventional method (dime-thyl-a-naphtylamine method). A good correlation was obtained between the sodium nitrite concentrations determined by the two methods (correlation coefficient 0.99). 

Several amines such as anilines, pyridine, etc., were perfluoroalkylated affording the corresponding ammonium or pyridinium salts [26-28], Other substrates which underwent perfluoroalkylation included triphenylphosphine [26], sodium nitrite [29], potassium thiocyanate [29] and potassium selenocyanate [29]. 

The popularity of the Nef reaction is due in part to the ready availability of nitro compounds. Primary and secondary halides react with sodium nitrite in dimeAyl sulfoxide (DMSO) or dimethylform-amide (DMF) to give useful yields of nitro compounds. Primary amines can be oxidized to nitro compounds with potassium permanganate, m-chloroperbenzoic acitP or ozone. Chlorination of oximes with hypochlorous acid and reduction with magnesium, zinc or hydrogen/lpalladium gives secondary nitro compounds. Stabilized carbanions can be nitrated by treauitent with a nitrate ester, and enol acetates are nitrated by acetyl nitrate to give nitro ketones. ... 

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