Iodide, magnesium

Alkyl and aryl iodides usually react with magnesium more rapidly than the corresponding bromides, and the bromides very much more rapidly than the chlorides. Aryl (as distinct from alkyl) chlorides have usually only a slow reaction with magnesium and are therefore very rarely used. With alkyl and aryl iodides in particular, however, a side reaction often occurs with the formation of a hydrocarbon and magnesium iodide ... 

Note that ethylene oxide reacts with the Grignard reagent to gi e a 2-substi tuted ethanol e.g. with methyl magnesium iodide ... 

Dimethyl ethyl carbinol (2-methy 1-2-butanol or amyl alcohol), CH3CHjCOH(CH3).2. From ethyl propionate and methyl magnesium iodide. Collect the tertiary alcohol at 100-102°. 

The rate of the reaction decreases with increasing number of substituents in the acetylenic halide, and it is higher with acetylenic bromides than with the corresponding chlorides. Methyl magnesium iodide gives equal amounts of 1,1- and 1,3--substitution products, whereas tert.-butylmagnesium bromide does not react. However, for some tert.-butyl substituted allenes there exists an attractive com-... 

Properties. Magnesium iodide [10377-58-9] can exist as two dehquescent andheat sensitive compounds the octahydrate [7790-31-0],... 

Table 16. Physical Properties of Magnesium Iodide and Hydrates ...

Magnesium iodide is soluble in alcohols and many other organic solvents, and forms numerous addition compounds with alcohols, ethers, aldehydes, esters, and amines. One example is magnesium iodide dietherate [29964-67-8], Mgl2 prepared by gradual addition of iodine to a... 

Uses. Magnesium iodide is used in the deoxygenation of oxiranes into olefins and iodine. This step is important to organic chemistry because it helps in the stmcture elucidation of complex organic molecules (110). Eor example. 

Benzopinacol has been prepared by the action of phenylmag-nesium bromide on benzil 1 or methyl benzilate. Usually it has been obtained by reduction of benzophenone, the reducing agents being zinc and sulfuric acid or acetic acid, aluminum amalgam, and magnesium and magnesium iodide. The present... 

Magnesium iodide [10377-58-9] M 278.1, m 634°. Crystd from water (1.2mL/g) by partial evapn in a desiccator. 

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. 

Trichloroacetanilide has been prepared from hexachloroacetone and aniline, from trichloroacetyl chloride and aniline, by the action of aniline magnesium iodide on ethyl trichloroacetate, by heating N-phenyltrichloroacetimidyl chloride with dilute methanol, and from trichloroacetic acid and aniline in the presence of phosphorus oxychloride. ... 

Rao prepared 2a-methyl-5a-cholestan-2i -ol (5) by reaction of methyl-magnesium iodide with 5a-cholestan-2-one (4). The 2i -configuration of the hydroxyl group was established by converting (5) to the 2a-methyl-2j5,19-epoxide (6) with lead tetraacetate and iodine in boiling benzene. 

Epoxide (88) is converted to C-norpregnane (89) in 60% yield by methyl-magnesium iodide in refluxing ether-benzene. No rearrangement to the C-norsteroid occurs with dimethylmagnesium. 

Oddo reported over 50 years ago that the interaction of methyl iodide with indole magnesium iodide at the reflux temperature of ether for 12 hours produced 3-methylindole (2). Rather surprisingly,... 

Allyl-3-methylindolenine (37) was also synthesized by the action of methyl iodide on 3-allylindole magnesium iodide however, the yield of 37 was not as good as that obtained in the procedure starting from 3-methylindole. ... 

Methyl-3-re-propylindole (43) was obtained by hydrogenation of the intermediate 2-methyl-3-allylindole (44), obtained by the allylation of 2-methylindole magnesium iodide. There were no reports of isomeric products being formed in this reaction. ... 

Jackson and Smith further showed that crotyl bromide reacts with 3-methylindole magnesium iodide to give a mixture of products from which l- i-butyl-3-methylindole (45) and 2-w-but5d-3-methylindole... 

Ganellin and Ridley obtained a mixture of isomeric products by the action of 2-ehloro-l dimcthylaminopropane on indole magnesium iodide. In this case both 3-(2-dimethylamino-l-methylethyl)... 

Powers reported recently that 3- 2-pyridyl)indole (103) is obtained in ca. 17% yield by the interaction of 2-chloropyridine with indole magnesium iodide in a sealed tube at 160° for 12 hours.3-(3-Cyano-... 

Bruce and Sutcliffe obtained l-acetyl-2-methyl-3-phenylindole (123) by the action of acetyl chloride on 2-methyl-3-pheiiylindole magnesium iodide in ether.These authors were able to obtain l-benzoyl-2-benzyl-3-phenylindole (124) but not l-acetyl-2-benzyl-3-phenylindole (125) from 2-benzyl-3-phenylindole magnesium iodide by analogous procedures.3-Acetyl-2-phenylindole (126) and 3-propionyl-2-pheny]indole (127) have recently been prepared in fair yield by the acylation of 2-phenylindole magnesium iodide with acetyl and propionyl chloride, respectively. Le ete obtained a mixture of l-acetyl-3-ethylindole (128) and 2-acetyl-3-ethylindole (129) by the interaction of acetyl chloride with 3-ethylindole magnesium iodide in ether. 

Kalir and Szara obtained l,3-bis(a-chloropropionyl)indole (140) by the action of a 20% excess of a-chloropropionyl chloride on indole magnesium bromide in an ether-toluene mixture. On the other hand, Ganellin and Ridley obtained 3-(o -chloropropionyl)indole (141) by the action of a 10% excess of a-chloropropionyl chloride on indole magnesium iodide in anisole. -... 

Benzhydryl 2-methyl-3-indolyl ketone (201) has been prepared by the action of diphenylacetyl chloride on 2-methylindole magnesium iodide. ... 

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