Magnesium alkyl- halides

On catalytic hydrogenation it furnishes mainly dihydroquinidine. Benzoyl chloride converts it into the enol benzoate, m.p. 114-5°, and on interaction with magnesium alkyl halides it forms alkylquinidines, e.g., methylquinidine, 2H2O, m.p, 105-12°, [a] ° -(- 168° (EtOH),... 

Mercury alkyls are readily obtained by the actions of Grignard reagents (magnesium alkyl halides) on mercury(II) chloride. Thus, mercury dimethyl is made from magnesium methyl chloride and mercury(II) chloride ... 

It may be mentioned that the Grignard reaction can also be applied to the production of primary alcohols by the interaction of ethylene oxide and magnesium alkyl halide. 

Reaction XLIII. (a) Formation of Esters by the action of Acid Anhydrides or of Acid Chlorides on an Alcohol in the presence of Magnesium Alkyl Halide (Grignard). (B., 39, 1738.)—This application of the Grig-nard reaction to the preparation of esters is of theoretical rather than practical interest as illustrating the wide applicability of this many-sided reaction. The steps in the synthesis will be clear from the examples given they are somewhat different from the usual phases of a Grignard reaction. 

Reaction XLIII. (b) Formation of Ethyl Esters by the Action of Ethyl Chloroformate on Magnesium Alkyl Halide in Dry Ethereal Solution (Grignard).—This is another mode of application of the Grignard reaction to the synthesis of esters. It is more direct than the previous method. 

I. Sehottle on benzene sulphonate, by A. Seyewetz and L. Poizat on phenyl hydrazine, by E, Fischer on zinc ethyl and magnesium alkyl halides, by F. Ebler and R. L. Krause on metaphosphoric esters and phosphorous esters, by W. Streoker and H. Heuser etc. 

By treating magnesium alkyl halides with arsenic trihalides ... 

This compound is prepared in an ether solution, and it is believed that the ether enters into the product and that the formula is probably not the simple magnesium alkyl halide, but is... 

The first organic compound of boron was isolated by Frankland in 1862, by the interaction of zinc methyl and triethyl borate. This method and the use of zinc alkyls with boron trichloride was continued until the discovery of the Grignard reagent. In 1900 boron tri-methyl was prepared by the action of magnesium methyl iodide on trimethyl borate, and in 1921 a number of boron trialkyls were obtained by the interaction of magnesium alkyl halides and boron trifluoride. Of the derivatives of the type RgB, boron trimethyl is a gas, spontaneously inflammable in air boron triethyl, a spontaneously inflammable liquid whilst the higher members of the series are liquids, readily oxidised when exposed to air. The metl yL fpd ethyl derivatives combine with ammonia to foriii IliS type I BOH only... 

The alkyl boric acids, RB(OH), ff s jb prepared by the action of magnesium alkyl halides on boric iJ llilhey are all solids, and the lower members of. the series are volatile at low temperatures. ... 

Table XIII. of the Appendix gives a list of compounds prepared by the following general method, together with their physical constants, Three times the ealeulated quantity of magnesium alkyl halide is used, and after the introduction of the tin alkyl halides the mixture is boiled under reilux for two hours, the etlier removed, and the residue baked on the water-buth lor one liour. After cooling, ether is added, and the whole deosed with water. Mixed tin tetra-alkyls are converted into inixed tin trialkyl bromides of the type R R SnX by the action of bromine at - 40° to —30° C., ati alkyl group being split out, this resembling the bromination of lead alkyls.

Lead tetra-alkyls containing one or two secondary radicles can easily be obtained by the action of lead alkyl mono- or dihalides on secondary magnesium alkyl halides, win 1st those containing three secondary radicles are derived ] )rimaril,y from the tctra-alkyls. Table XX. of the Appendix gives a list of these compounds, together with their physical constants. 

Another method of preparing acids which is applicable in certain cases is that discovered by Grignard. It will be recalled that this investigator showed that when magnesium is added to a solution of an alkyl halide in ether or other apropriate solvent, a compound is formed which reacts readily with other substances. If the magnesium alkyl halides so prepared are treated with carbon dioxide, the gas is absorbed and an addition-product is formed, which on treatment with water yields an acid. The reactions in the case of the preparation of acetic acid are expressed by the following equations —... 

Aldehydes form addition-products with the magnesium alkyl halides, from which secondary alcohols may be obtained by decomposition with water. These reactions have been much used in the preparation of alcohols of this class. The reactions are indicated by the following equations — H H... 

It will be noted that in the addition of the magnesium alkyl halide, the positive metallic atom remains in combination with the halogen atom and unites with the oxygen of the aldehyde, while the alkyl group joins itself to carbon. The way in which the union takes place should be noted, as the magnesium alkyl halides are much used in synthetic work, and in the formation of addition-products with compounds containing oxygen, the union takes place in a manner similar to that just explained. 

Ketones can be prepared by the replacement of the halogen atom of an acyl halide (e.g. CH3COCI) by an alkyl group. This replacement can be effected as the result of the action of certain organic compounds which contain metals. The zinc alkyls or magnesium alkyl halides are generally used. Methyl ethyl ketone can be prepared in this way from acetyl chloride and magnesium ethyl iodide —... 

An intermediate product is formed as the result of the addition of the acid chloride and magnesium alkyl halide, the addition taking place in a way similar to that which has been explained (180). This synthetic method is an important one, as it serves to replace a halogen atom in an acyl halide by an alkyl group. 

Duck et al. These systems are of particular interest in that they combine the use of a hydroxyl-containing support with a magnesium alkyl halide compound. Activities of some two orders of magnitude (on the basis of Ti) greater than that of a traditional TiCU catalyst were reported although no actual active centre determinations were carried out Also in this case much higher ratios of AI Ti were employed (typically 240 1) than for traditional catalysts although the actual alkyl aluminium concentration employed was about the same in both cases. 

---