Magnesium amalgam reduction with

Hyponitrites can be prepared in variable (low) yields by several routes of which the commonest are reduction of aqueous nitrite solutions using sodium (or magnesium) amalgam, and condensation of organic nitrites with hydroxylamine in NaOEt/EtOH ... 

Somewhat less frequent than the reductions of aliphatic ketones to secondary alcohols and to hydrocarbons are one-electron reductions to pinacols. These are accomplished by metals such as sodium, but better still by magnesium or aluminum. Acetone gave 43-50% yield of pinacol on refluxing with magnesium amalgam in benzene [140], and 45% and 51% yields on refluxing in methylene chloride or tetrahydrofuran, respectively [825. ... 

These dimerizations are analogous to those of the radical anions R2C 0 which are intermediates in the reduction of ketones to pinacols. Indeed, in the presence of magnesium amalgam, pyridine condenses with acetophenone to give alcohol 396 by oxidation of the intermediate dihydropyridine. In a similar reaction type, pyridine with zinc and acetic anhydride or ethyl chloroformate yields (397 R = Me or OEt, respectively). 

Perfluorinated ketones form stable hydrates, (Rp)2C(OH)2, and these diols are very acidic. Hexafluoroacetone hydrate is known to be a very good solvent and is particularly useful for certain polymers [112, 152]. Perfluoropinacol may be obtained from hexafluoroacetone by photolytic reduction (Figure 8.44), whilst classical reduction with magnesium amalgam gives only low yields [112]. The same pinacol is also obtained by heating 8.44A, which is produced as shown in Figure 8.44 [153]. 

Transition metal carbonyl derivatives of magnesium can be prepared readily by the reductive cleavage of the metal-metal bond in numerous dimeric transition metal carbonyl complexes or by the removal of halogen from transition metal carbonyl halide complexes with an excess of 1 % magnesium amalgam in the presence of a Lewis base. These preparations may be represented by the general equations... 

Low-valent titanium metal species [Ti(II), Ti(I), Ti(0)] are generated by reduction of TiCl4 with magnesium amalgam" or by reduction of TiCl3 with either Li, K, Zn-Cu... 

Corey-Winter olefin synthesis (1, 1233-1234 2,439-441 3,315-316 4, 269-270, 541-542 5,34, 661). Vedejs and Wu converted thionocarbonates into olefins by alkylation with methyl iodide (90°, DME, sealed tube) followed by reduction (zinc dust—ethanol or magnesium amalgam—THF). This two-step procedure was used for preparation of the cyclobutene (2) in this case the reaction with triethyl phosphite was immeasurably slow. 

The reduction of 2-butanone with magnesium amalgam produces, after hydrolysis, two isomeric glycols. What are their structures ... 

The present procedure was developed from those of Wallach and Freylon, based upon the general method discovered by Leuckart. a-Phenylethylamine also can be prepared satisfactorily by the reduction of acetophenone oxime with sodium and absolute alcohol or sodium amalgam, but the reagents are more expensive and the processes less convenient. The amine has been obtained by reducing acetophenone oxime electro-lytically, by reducing acetophenone phenylhydrazone with sodium amalgam and acetic acid, from a-phenylethyl bromide and hexamethylenetetramine, and by the action of methyl-magnesium iodide upon hydrobenzamide, as well as by other methods of no preparative value. 

In 1808, Sir Humphry Davy reported the production of Mg in the form of an amalgam by electrolytic reduction of its oxide using a Hg cathode. In 1828, the Fr scientist A. Bussy fused Mg chloride with metallic K and became the first to produce free metallic Mg. Michael Faraday, in 1833, was the first to produce free metallic Mg by electrolysis, using Mg chloride. For many years, however, the metal remained a laboratory curiosity. In 1886, manuf of Mg was undertaken on a production scale in Ger, using electrolysis of fused Mg chloride. Until 1915, Ger remained the sole producer of Mg. However, when a scarcity of Mg arose in the USA as a result of the Brit blockade of Ger in 1915, and the price of Mg soared from 1.65 to 5.00 per lb, three producers initiated operations and thus started a Mg industry in the USA. Subsequently, additional companies attempted production of Mg, but by 1920 only two producers remained — The Dow Chemical Co (one of the original three producers) and. the American Magnesium Corn. In 1927. the latter ceased production, and Dow continued to be the sole domestic producer until 1941. The source of Mg chloride was brine pumped from deep wells. In 1941, Dow put a plant into operation at Freeport, Texas, obtaining Mg chloride from sea-... 

---