Magnesium diethyl, reaction+hexyne

The heat of reaction brought about refluxing during the addition of the 2-bromo-3-hexyne, and when the addition was complete the reaction mixture was heated to refluxing for a further period of 30 minutes. A sufficient amount of water was then added to the reaction mixture to dissolve the sodium bromide which had formed, and the only organic layer was separated, washed with water and dried over anhydrous magnesium sulfate. The dried organic layer was then fractionally distilled under reduced pressure, and the diethyl (1-methyl-2-pentynyl) malonate formed in the reaction was collected at about 117° to 120°C at the pressure of 2 mm of mercury. 

Halogen-free diethylmagnesium reacted with 1-hexyne three times as fast as ethylmagnesium bromide [85]. By (partial) removal of magnesium bromide from such a solution, through the addition of various amounts of 1,4-dioxane and measuring the relative rate of reaction of that solution with 1-hexyne, it was expected that information could be obtained about the position of the Schlenk equilibrium. Dioxane itself had no influence on the rate of reaction of diethylmagnesium in diethyl ether. The results were rather inconclusive. 

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