Ethers lithium chloride

Exp. 4) in 10 min with cooling at -30°C. After an additional 15 min 0.30 mol of a-chlororaethyl ethyl ether (note 2) was introduced in 10 min, while keeping the temperature between -20 and -30°C. A white precipitate of lithium chloride was formed. The cooling bath was then removed and the temperature was allowed to rise to +10°C. The mixture was hydrolyzed by shaking it with 200 ml of a solution of 30 g of ammonium chloride, to which 5 ml of aqueous ammonia had been added. 

Technora. In 1985, Teijin Ltd. introduced Technora fiber, previously known as HM-50, into the high performance fiber market. Technora is based on the 1 1 copolyterephthalamide of 3,4 -diaminodiphenyl ether and/ -phenylenediamine (8). Technora is a whoUy aromatic copolyamide of PPT, modified with a crankshaft-shaped comonomer, which results in the formation of isotropic solutions that then become anisotropic during the shear alignment during spinning. The polymer is synthesized by the low temperature polymerization of/ -phenylenediamine, 3,4 -diaminophenyl ether, and terephthaloyl chloride in an amide solvent containing a small amount of an alkaU salt. Calcium chloride or lithium chloride is used as the alkaU salt. The solvents used are hexamethylphosphoramide (HMPA), A/-methyl-2-pyrrohdinone (NMP), and dimethyl acetamide (DMAc). The stmcture of Technora is as follows ... 

Although most of the lithium chloride separates from the ether solution as a finely divided solid during the reaction, additional small quantities of lithium chloride continue to separate for 12-14 hr. After standing overnight, a typical reaction contains a precipitate of finely divided brownish-pink solid below a clear, pale yellow solution. 

The reaction of lithium with methyl chloride in ether solution produces a solution of methyllithium from which most of the relatively insoluble lithium chloride precipitates. Ethereal solutions of halide-free" methyllithium, containing 2-5 mole percent of lithium chloride, were formerly marketed by Foote Mineral Company and by Lithium Corporation of America, Inc., but this product has been discontinued by both companies. Comparable solutions are also marketed by Alfa Products and by Aldrich Chemical Company these solutions have a limited shelf-life and older solutions have often deteriorated... 

The determination of position of protonation by reaction with diazomethane was performed as follows The enamine was treated at —70° with ethereal hydrogen chloride and the suspension of precipitated salt was treated with diazomethane and allowed to warm slowly to —40°, at which temperature nitrogen was liberated. The reaction with lithium aluminum hydride (LAH) was carried out similarly except that an ether solution of LAH was added in place of diazomethane. The results from reaction of diazomethane and LAH 16) are summarized in Table 1. 

Organolithium compounds can readily be prepared from metallic Li and this is one of the major uses of the metal. Because of the great reactivity both of the reactants and the products, air and moisture must be rigorously excluded by use of an inert atmosphere. Lithium can be reacted directly with alkyl halides in light petroleum, cyclohexane, benzene or ether, the chlorides generally being preferred ... 

A solution of 20.0 g. (0.105 mole) (Note 6) of p-toluenesulfonyl chloride in 100 ml. of anhydrous.ether is then injected into the addition funnel, and this solution is added over a period of 30 minutes to the red reaction mixture at 0° with stirring. The red color immediately disappears upon addition. After addition is complete, 4.2 g. (0.1 mole) of anhydrous lithium chloride (Note 7) is added. The reaction mixture is warmed to room temperature and stirred overnight (18-20 hours), during which time lithium p-toluenesulfonate precipitates. 

Kollig, H.P., Ellington, J.J., Weber, E.J., and Wolfe, N.L. Environmental research brief - Pathway analysis of chemical hydrolysis for 14 RCRA chemicals. Office of Research and Development. U.S. EPA Report 600/M-89/009, 1990, 6 p. Kolthoff, I.M. and Chantooni, M.K., Jr. Crown ether complexed alkali metal picrate ion pairs in water-saturated dichloro-methane as studied by electrolytic conductance and by partitioning into water. Effect of lithium chloride on partitioning, J. Chem. Eng. Data, 42(l) 49-53, 1997. 

Reduction of dibenzothiophene with sodium in liquid ammonia has been shown to be sensitive to the experimental methods employed however, the major product is usually 1,4-dihydrodibenzothiophene. 27 -28i The electrochemical reduction of dibenzothiophene in ethylene-diamine-lithium chloride solution has been shown to proceed via stepwise reduction of the aromatic nucleus followed by sulfur elimination. In contrast to the reduction of dibenzothiophene with sodium in liquid ammonia, lithium in ethylenediamine, or calcium hexamine in ether, electrolytic reduction produced no detectable thiophenol intermediates. Reduction of dibenzothiophene with calcium hexamine furnished o-cyclohexylthiophenol as the major product (77%). Polaro-graphic reduction of dibenzothiophene 5,5-dioxide has shown a four-electron transfer to occur corresponding to reduction of the sulfone group and a further site. ... 

Reduction of o /i-unsatin-ated lactams, S,6-dihydro-2-pyridones, with lithium aluminum hydride, lithium alkoxyaluminum hydrides and alane gave the corresponding piperidines. 5-Methyl-5,6-dihydro-2-pyridone (with no substituent on nitrogen) gave on reduction with lithium aluminum hydride in tetrahydrofuran only 9% yield of 2-methylpiperidine, but l,6-dimethyl-5,6-dihydro-2-pyridone and 6-methyl-l-phenyl-5,6-dihydro-2-pyridone afforded 1,2-dimethylpiperidine and 2-methyl-1-phenylpiperidine in respective yields of 47% and 65% with an excess of lithium aluminum hydride, and 91% and 92% with alane generated from lithium aluminum hydride and aluminum chloride in ether. Lithium mono-, di- and triethoxyaluminum hydrides also gave satisfactory yields (45-84%) [7752]. 

In an electrolytic cell (Fig. 5) consisting of platinum electrodes (2 cm x 5 cm in area) and cathode and anode compartments separated by an asbestos divider, each compartment is charged with 17 g (0.4 mol) of lithium chloride and 450 ml of anhydrous methylamine. Isopropylbenzene (12 g, 0.1 mol) is placed in the cathode compartment and a total of 50,000 coulombs (2.0 A, 90 V) is passed through the solution in 7 hours. After evaporation of the solvent the mixture is hydrolyzed by the slow addition of water and extracted with ether the ether extracts are dried and evaporated to give 9.0 g (75%) of product boiling at 149-153° and consisting of 89% of a mixture of isomeric isopropylcyclohexenes and 11% of recovered isopropylbenzene. 

Substituted cyclohexanones, bearing a methyl, isopropyl, tert-butyl or phenyl group, give, on deprotonation with various chiral lithium amides in the presence of chlorotrimethylsilane (internal quench), the corresponding chiral enol ethers with moderate to apparently high enantioselec-tivity and in good yield (see Table 2)13,14,24> 29 36,37,55. Similar enantioselectivities are obtained with the external quench " technique when deprotonation is carried out in the presence of added lithium chloride (see Table 2, entries 5, 10, and 30)593. 

The support originally used for solid-phase synthesis was partially chloromethy-lated cross-linked polystyrene, which was prepared by chloromethylation of cross-linked polystyrene with chloromethyl methyl ether and tin(IV) chloride [1-3] or zinc chloride [4] (Figure 6.1). Haloalkylations of this type are usually only used for the functionalization of supports, and not for selective transformation of support-bound intermediates. Because of the mutagenicity of a-haloethers, other methods have been developed for the preparation of chloromethyl polystyrene. These include the chlorination of methoxymethyl polystyrene (Figure 6.1 [5]), the use of a mixture of dimethoxymethane, sulfuryl chloride, and chlorosulfonic acid instead of chloromethyl methyl ether [6], the chlorination of hydroxymethyl polystyrene [7], and the chlorination of cross-linked 4-methylstyrene-styrene copolymer with sodium hypochlorite [8], sulfuryl chloride [8], or cobalt(III) acetate/lithium chloride [9] (Figure 6.1, Table 6.1). 

Fig. 5. Phase separation temperature changes of the aqueous solutions of PNIPAM containing pendant 11.6 mol % crown ether groups by the addition of potassium chloride (O), sodium chloride (3), lithium chloride (C), and cesium chloride ( ). Polymer concentration was 1 mass %...

Methods for the preparation of aluminum trihydride-diethyl etherate, AlHa O.SffC Hs )20], t have been published,1,2 but the absence of complete experimental details makes duplication difficult. The following procedure is a modification of that reported by Finholt, Bond, and Schlesinger.1 Problems inherent in previous methods, such as premature precipitation, decomposition of the alane, and lithium chloride contamination, are avoided. 

Potassium borohydride (1.0 g, 20 mmol), anliydrous lithium chloride (0.8 g, 20 mmol) were thoroughly mixed in a mortar and transferred to a flask (100 mL) connected with reflux equipment, then dry THF (10 mL) was added and the mixture was heated to reflux for 1 h. After cooling, the ester (10 mmol) was added and stirred for 0.5 h at room temperature, then the THF was removed under reduced pressure. After the mixture was irradiated by microwave for 2-8 min, the mixture was cooled to room temperature, water (20 mL) was added, extracted with ether (3 x 15 mL), dried with magnesium sulfate, and evaporated to give the crude product, which was purified by crystallization, distillation or column chromatography. 

ESTERS Sodium benzeneselenolate. ETHERS Boron tribromide-Sodium iodide-15-Crown-5. Boron trifluoride etherate. Ferric chloride-Silica. Lithium iodide. Silicon(IV) chloride-Sodiuiu iodide. Sodium iodide-Pivaloyl chloride. 2,4,4,6-Tetrabromocyclohexadiene. Trichloro(methyl)silane. 

The 3-keto-84 system is introduced by conventional methods, that is, by oxidation of the 3-hydroxy group to a 3-keto group with chromic oxide. Bromination at the 4-position, and finally dehydrobromination with dinitrophenylhydrazine or with lithium chloride in dimethylformamide were carried out to give acetic acid lip-hydroxy-3,18,20-trione-pregn-4-ene lip,18-lactone 17-oxoethyl ether. 

Bromo-l-(4-fluorophenyl)-l-(3-dimethylaminopropyl)-l,3-dihydroisobenzofuran Magnesium Butyl lithium tert-Butyl methyl ether Isopropylmagnesium chloride Thionyl chloride Sulfamide Dry ice... 

Lithium chloride (2.6 g) is dissolved in THF (170 mL). Dimethyl-(2-oxo-4-phenylbutyl)phosphonate (7.87 g) and triethylamine (4.3 mL) are added. The mixture is stirred and cooled to -10°C. A solution of the Corey aldehyde benzoate, (lS,5R,6R,7R)-6-formyl-7-(benzyloxy)-2-oxabicyclo[3.3.0]octan-3-one (8.42 g) in THF (75 mL) is added to the reaction mixture over three hours. The resulting mixture is stirred for 18 hours at -10°C. At the end of this time, methyl t-butyl ether (MTBE) (100 mL) is added and the mixture warmed to 0-20°C. Sodium bisulfite (38%, 100 mL) is added and the two-phase mixture was stirred for 10 min. The phases are separated and the organic phase is washed with saturated aqueous sodium bicarbonate solution (100 mL). The organic phase is separated and concentrated under reduced pressure to a volume of <100 mL. Ethyl acetate (200 mL) is added and the... 

N-Methyl-2-pyrrolidone Ferric chloride hexahydrate Glycol monomethyl ether Lithium aluminum hydride Ruthenium on charcoal Magnesium ethoxide 4-Toluenesulfonic acid Sodium bicarbonate 1,2,3,4-Tetrafluoro benzene Palladium on charcoal Cyclopropylamine N-benzylimide... 

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