Magnesium ethoxide

Reaction (1) usually proceeds readily provided the magnesium is activated with iodine and the water content does not exceed one per cent. Subsequent interaction between the magnesium ethoxide and water gives the highly insoluble magnesium hydroxide only a slight excess of magnesium is therefore necessary. 

The absolute ethyl alcohol employed in the condensation was refluxed over calcium oxide for 20 hours and finally distille from magnesium ethoxide. 

Magnesium ethylate (magnesium ethoxide) [2414-98-4] M 114.4. Dissolve ca Ig of solid in 12.8mL of absolute EtOH and 20mL of dry xylene and reflux in a dry atmosphere (use CaCl2 in a drying tube at the top of the condenser). Add lOmL of absolute EtOH and cool. Filter solid under dry N2 and dry in a vacuum. Alternatively dissolve in absolute EtOH and pass through molecular sieves (40 mesh) under N2, evap under N2, and store in a tightly stoppered container. [J Am Chem Soc 68 889 1964 ]... 

A solution of 0.9 mmol of the imine and l.2mmol of diethyl pyrocarbonate in 1.5 mL of dry ethanol (distilled from magnesium ethoxide) is stirred under nitrogen at 60 C for 24 h. Then the solvent is removed in vacuo and the residue flash chromatographed (silica gel, ethyl acetate/hexane 1 5) to give the product as an oil. 

It is important to maintain strictly anhydrous conditions throughout this reaction. The equipment should be carefully predried and the absolute ethanol freshly prepared (preferably by the magnesium ethoxide method2) and distilled directly into the reaction flask. If the volume of ethanol is less than 2.5 1. the sodium ethoxide may not remain in solution. It is convenient to employ a three-necked flask carrying two condensers for this operation and to add the sodium through the third neck, which is otherwise kept stoppered. 

Drying methods, diethyl phthalate, 31, 2 magnesium ethoxide, 31, 2 Dulcin, 31,10... 

They are easily prepared from Grignard reagents, magnesium ethoxide or with the complex magnesium chloride-trialkylamine (see Section II where the generation of these reagents is discussed). The acylation of anions derived from malonates can be achieved with acyl chlorides, acyl imidazoles, aUcoxycarbonylimidazoles or mixed anhydrides. 

The Bayer synthesis of ciprofloxacin (1) patented in 1981 utilized 2,4-dichloro-5-fluorobenzoyl chloride (15) as the starting material. With the aide of magnesium ethoxide, condensation of acid chloride 15 and diethyl malonate assembled ketone 16, which was subsequently decarboxylated using tosylic acid to form ethyl 2,4-dichloro-5-fluorobenzoylacetate (17) in 82% yield in two steps from 15. A Dieckman-like condensation of 17 with ethyl orthoformate was carried out in refluxing acetic anhydride... 

Ethylhexanol is usually produced by subsequent aldolization of butyraldehyde produced in the oxo reaction followed by hydrogenation of the intermediate unsaturated aldehyde.89 In Esso s Aldox process, however, in situ aldol condensation is effected by suitable promoters.11 Magnesium ethoxide and soluble zinc compounds are recommended to promote controlled aldolization during the oxo reaction. The Shell variant uses potassium hydroxide. Serious disadvantages (mixed aldolization with the branched aldehyde, problems associated with recycling of the additives), however, prevented wider use of the Aldox process. 

A chlorocarbonyl group ortho to a fluorine atom activates the halogen towards nucleophilic displacement. In the synthesis of a number of polyfluorinated chromones the 1,3-diketo side-chain is introduced using ethyl acetoacetate in the presence of magnesium ethoxide. Cyclization occurs on addition of sulfuric acid (70JOC930). 

The solvent is available commercially in pure form. Distillation from magnesium ethoxide [64] affords fairly dry material (H20 content = 50 ppm), but a better job can be done H20 content = 18 ppm can be obtained by allowing the alcohol to stand over powdered 3-A molecular sieve [52]. It is important that the molecular sieve be powdered the more commonly found beads only reduce the water content to 99 ppm. 

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... 

To magnesium ethoxide (5.9 g) was added diethyl malonate (7 g) in anhydrous toluene (35 ml) dropwise and the mixture was warmed for 2 h at 50° to 60°C and then cooled to -10°C. To the mixture was added a solution of the acid chloride (8.86 g) in anhydrous toluene (10 ml) dropwise over 15 min. After stirring for 1 h at -5° to 0°C, ice water (30 ml) containing concentrated sulfuric acid (8 ml) was added to the mixture and the organic layer was separated. The organic layer was washed with saturated saline solution, dried over anhydrous sodium sulfate and then concentrated to give diethyl 3-methoxy-2,4,5-trifluorobenzoylmalonate (13.64 g) as brown oil. 

The possibility of synthesizing MgO powders from liquid precursors by a sol-gel route involving the hydrolysis and condensation of magnesium ethoxide has been examined by several researchers.[44,45] Excellents results were reported by Kla-bunde et a/.[46,47] using a method involving the formation of Mg(OH)2 gel from Mg(OCH3)2. Heat treatment of Mg(OH)2 precursor at 773 K under vacuum yielded the dehydrated MgO with a 500 m2 g 1 surface area and 4.5 nm crystallite size. 

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