Calcium-Amines

REDUCTION, REAGENTS Bis(N-methylpi-perazinyl)aluminum hydride. Borane-Di-methyl sulfide. Borane-Tetrahydrofurane. Borane-Pyridine. n-Butyllithium-Diisobu-tylaluminum hydride. Calcium-Amines. Diisobutylaluminum hydride. 8-Hydroxy-quinolinedihydroboronite. Lithium aluminum hydride. Lithium 9-boratabicy-clo[3.3.1]nonane. Lithium n-butyldiisopro-pylaluminum hydride. Lithium tri-j c-butylborohydride. Lithium triethylborohy-dride. Monochloroalane. Nickel boride. 2-Phenylbenzothiazoline. Potassium 9-(2,3-dimethyl-2-butoxy)-9-boratabicy-clo[3.3.1]nonane. Raney nickel. Sodium bis(2-methoxyethoxy)aluminum hydride. Sodium borohydride. Sodium borohy-dride-Nickel chloride. Sodium borohy-dride-Praeseodymium chloride. So-dium(dimethylamino)borohydride. Sodium hydrogen telluride. Thexyl chloroborane-Dimethyl sulfide. Tri-n-butylphosphine-Diphenyl disulfide. Tri-n-butyltin hydride. Zinc-l,2-Dibromoethane. Zinc borohydride. 

Aromatic hydrocarbons can be reduced to cycloalkenes by calcium dissolved in a mixture of methylamine and ethylenediamine. For example, calcium reduction of p-xylene (57) and anthracene (59) gives 1,4-dimethyl-l-cyclohexene (58) or decahydroanthracene (60) in 84% and 85% yield, respectively (Scheme 4.16). Calcium-amine combinations are different from lithium-amine systems in that they have little or no propensity to reduce internal double bonds despite the large excess of calcium employed. A grayish white precipitate, seemingly calcium alkyl amide. 

When tert-butyl alcohol is used with the calcium-amine system, aromatic compounds can be reduced to products identical with those obtained by Birch reduction of the same substrates [37]. Advantages of the calcium-amine-alcohol procedure are, first, that calcium is much safer to handle than sodium and lithium and is therefore more amenable to large-scale reductions, and, second, the amine solvents are relatively high-boiling and are, therefore, much easier to manipulate than liquid ammonia. 

Reactions carried out on disaccharide derivatives included the conversion of peracetates to l-phenylthio- 3-derivatives by use of phase-transfer methods and the epimerization at C-2 by calcium -amine systems (CaCl2.2H20, EtjN, for example). By this means maltose, lactose, isomaltose and melibiose were converted into the corresponding glucosyl-D-mannoses. An extensive range of variously substituted maltosyl fluorides have been made from maltose derivatives as substrates for cyclodextrin transferase. Only the 6 -methyl ether and 6 -acetate were transformed into cyclic products. In the course of the work the thio-derivatives (83) and (84) were made. ... 

Cannot be used for alcohols, phenols or amines, with all of which it combines. Not advisable for acidic liquids, as ordinary calcium chloride always contains some calcium hydroxide owing to partial hydrolysis during preparation. Usually used for alcohols (see p. 88). Cannot be used for acidic compounds, nor for esters, which it would hydrolyse. 

The industrial process for preparing the reagent usually permits a little hydrolysis to occur, and the product may contain a little free calcium hydroxide or basic chloride. It cannot therefore be employed for drying acids or acidic liquids. Calcium chloride combines with alcohols, phenols, amines, amino-acids, amides, ketones, and some aldehydes and esters, and thus cannot be used with these classes of compounds. 

Metallic sodium. This metal is employed for the drying of ethers and of saturated and aromatic hydrocarbons. The bulk of the water should first be removed from the liquid or solution by a preliminary drying with anhydrous calcium chloride or magnesium sulphate. Sodium is most effective in the form of fine wire, which is forced directly into the liquid by means of a sodium press (see under Ether, Section II,47,i) a large surface is thus presented to the liquid. It cannot be used for any compound with which it reacts or which is affected by alkalis or is easily subject to reduction (due to the hydrogen evolved during the dehydration), viz., alcohols, acids, esters, organic halides, ketones, aldehydes, and some amines. 

Calcium chloride cannot be used to dry the ethereal solution because it combines with aniline (and other amines) to form molecular compounds. The best drying agent is sodium or potassium hydroxide (pellet form). 

Nickel halide complexes with amines give mixtures of linear polymer and cychc trimers (30). Nickel chelates give up to 40% of linear polymer (31). When heated with ammonia over cadmium calcium phosphate catalysts, propargyl alcohol gives a mixture of pyridines (32). 

Hoffman Degradation. Polyacrylamide reacts with alkaline sodium hypochlorite [7681-52-9], NaOCl, or calcium hypochlorite [7778-54-3], Ca(OCl)2, to form a polymer with primary amine groups (58). Optimum conditions for the reaction include a slight molar excess of sodium hypochlorite, a large excess of sodium hydroxide, and low temperature (59). Cross-linking sometimes occurs if the polymer concentration is high. High temperatures can result in chain scission. 

Hbls Process. Chemische Werke Huls AG has developed a process to produce soda ash and hydrochloric acid from salt via an amine—solvent system (12). A potential advantage of the Huls process is that, under some market conditions, hydrochloric acid may be more easily sold than either ammonium or calcium chloride. 

Other patents (81,82) coveted the preparation of cellulose solutions using NMMO and speculated about their use as dialysis membranes, food casings (sausage skins), fibers, films, paper coatings, and nonwoven binders. NMMO emerged as the best of the amine oxides, and its commercial potential was demonstrated by American Enka (83,84). Others (85) have studied the cellulose-NMMO system in depth one paper indicates that further strength increases can be obtained by adding ammonium chloride or calcium chloride to the dope (86). 

Maleic Anhydride. The ACGIH threshold limit value in air for maleic anhydride is 0.25 ppm and the OSHA permissible exposure level (PEL) is also 0.25 ppm (181). Maleic anhydride is a corrosive irritant to eyes, skin, and mucous membranes. Pulmonary edema (collection of fluid in the lungs) can result from airborne exposure. Skin contact should be avoided by the use of mbber gloves. Dust respirators should be used when maleic anhydride dust is present. Maleic anhydride is combustible when exposed to heat or flame and can react vigorously on contact with oxidizers. The material reacts exothermically with water or steam. Violent decompositions of maleic anhydride can be catalyzed at high temperature by strong bases (sodium hydroxide, potassium hydroxide, calcium hydroxide, alkaU metals, and amines). Precaution should be taken during the manufacture and use of maleic anhydride to minimize the presence of basic materials. 

Alkali moderation of supported precious metal catalysts reduces secondary amine formation and generation of ammonia (18). Ammonia in the reaction medium inhibits Rh, but not Ru precious metal catalyst. More secondary amine results from use of more polar protic solvents, CH OH > C2H5OH > Lithium hydroxide is the most effective alkah promoter (19), reducing secondary amine formation and hydrogenolysis. The general order of catalyst procUvity toward secondary amine formation is Pt > Pd Ru > Rh (20). Rhodium s catalyst support contribution to secondary amine formation decreases ia the order carbon > alumina > barium carbonate > barium sulfate > calcium carbonate. 

In the reduction of nitro compounds to amines, several of the iatermediate species are stable and under the right conditions, it is possible to stop the reduction at these iatermediate stages and isolate the products (see Figure 1, where R = CgH ). Nitrosoben2ene [586-96-9] C H NO, can be obtained by electrochemical reduction of nitrobenzene [98-95-3]. Phenylhydroxylamine, C H NHOH, is obtained when nitrobenzene reacts with ziac dust and calcium chloride ia an alcohoHc solution. When a similar reaction is carried out with iron or ziac ia an acidic solution, aniline is the reduction product. Hydrazobenzene [122-66-7] formed when nitrobenzene reacts with ziac dust ia an alkaline solution. Azoxybenzene [495-48-7], C22H2QN2O, is... 

Carbon Dioxide and Carbon DisulUde. Propylene oxide and carbon dioxide react ia the presence of tertiary amine, quaternary ammonium haUdes, or calcium or magnesium haUde catalysts to produce propylene carbonate (52). Use of catalysts derived from diethyUiac results ia polycarbonates (53). 

Steam and calcium hydroxide is formed. If the cooling water tends to form acid ia the boiler, either caustic or phosphate may be added to counteract the effect. When the cooling water tends to form base, only phosphate treatment is appropriate. Many dmm boilers that are operated on AVT have provision for phosphate or caustic treatment duriag condenser leaks because the amines used ia AVT have neither significant bufferiag capacity nor precipitate conditioning properties ia the boiler. 

Property ThioglycoHc acid ThioglycoHc acid Ammonium thioglycolate Glyceryl monothioglycolate Monoethanol amine thioglycolate Calcium thioglycolate... 

OC-Hydroxycarboxylic Acid Complexes. Water-soluble titanium lactate complexes can be prepared by reactions of an aqueous solution of a titanium salt, such as TiCl, titanyl sulfate, or titanyl nitrate, with calcium, strontium, or barium lactate. The insoluble metal sulfate is filtered off and the filtrate neutralized using an alkaline metal hydroxide or carbonate, ammonium hydroxide, amine, or alkanolamine (78,79). Similar solutions of titanium lactate, malate, tartrate, and citrate can be produced by hydrolyzation of titanium salts, such as TiCl, in strongly (>pH 10) alkaline water isolation of the... 

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