1.4- Dioxane industrial preparation

Summary Dioxane is prepared by treating ethylene glycol with sulfuric acid, and then distilling the mixture at 110 Celsius. After the distillation, the dioxane is treated with anhydrous calcium chloride to absorb water, and then the mixture is filtered. After filtration, the liquid is re-distilled. Commercial Industrial note Part or parts of this laboratory process may be protected by international, and/or commercial/industrial processes. Before using this process to legally manufacture the mentioned compound, with intent to sell, consult any protected commercial or industrial processes related to, similar to, or additional to, the process discussed in this procedure. This process may be used to legally prepare the mentioned compound for laboratory, educational, or research purposes. 

Problem 17.14 1,4-Dioxane is prepared industrially (for use as a water-soluble solvent) by dehydration of an alcohol. What alcohol is used ... 

Several Cs-units which have functional groups attached regioselectively, notably 2-methylbut-2-ene-l,4-dial-1-acetal (64), [3-(5,5-dimethyl-l,3-dioxan-2-yl)-but-2-enyl] triphenylphos-phonium chloride (65), 3-methylbut-2-ene-l,4-dial-1-acetal (66) and 3-ethoxycarbonylbut-2-en-l-yl diethylphosphonate (67) are key materials in the industrial syntheses of carotenoids. Methods for the preparation of these synthons are described in Chapter 3 Part I. 

Sulfation of alcohols with chlorosulfonic acid (Eq. 2) has been used in the laboratory and on an industrial scale to prepare sodium alkyl sulfates. The reaction is usually rapid in the presence or absence of solvents at 25-30°C and gives a product with little color. Unreactive solvents such as ether, dioxane, and halogenated hydrocarbons are commonly used in the sulfation reaction. Acetic acid has also been reported as a solvent for the sulfation of C5-C19 long-chain secondary alcohols. Table I gives several examples of the type of alcohols sulfated with chlorosulfonic acid. 

---