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Any ideas on how to get $\ce{C3H8O3}$ (Glycerol) from $\ce{CH4}$?

My theory is that by reacting $\ce{CH4}$ with $\ce{Cl2}$ (or $\ce{Br2}$), getting $\ce{CH3Cl}$, then Wurtz's method to $\ce{CH3CH3}$, adding $\ce{Cl2}$ (or $\ce{Br2}$) again, getting $\ce{CH3CH2Cl}$, then reacting with $\ce{NaOH}$ to get $\ce{CH3CH2OH}$, and finally $\ce{CH3CH2OH + CO2 + H2O}$ and getting glycerol ($\ce{C3H8O3}$), but my way seems rather off to me so I need some help.

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  • $\begingroup$ From methane?!?! $\endgroup$ – Jori Dec 19 '14 at 23:57
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Your synthesis is unlikely to become a huge commercial success ;)

Methylchloride is a technical product, but usually made by reaction of methanol with hydrogen chloride:

$$\ce{CH3OH + HCl -> CH3Cl + H2O}$$

This works nicely without side products, because

  • $\ce{CH3Cl}$ has a low solubility in water (around $\mathrm{5\,g\cdot L^{-1}}$)
  • under standard conditions, $\ce{CH3Cl}$ is a gas (bp around $\mathrm{-28\,°C}$)

The radical halogenation of methane will usually lead to various halogenation products and thus is not a good idea. The same is true for the similar reaction of ethane.

In addition, I fail to see how the reaction of ethanol and carbon dioxide will lead to glycerol.

You should further take into account that there's plenty of glycerol available as a side product in the production of biodiesel.

From a commercial and ecological point of view, methane therefore is better converted to cabon monoxide and hydrogen by steam reformation. Further hydrogen may be obtained from a subsequent shift reaction and the resulting carbon dioxide may be reacted with gycerol to yield 1,2-glycerol carbonate.

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    $\begingroup$ Radical chlorination of hydrocarbons was done till the 70ties. As long as there was demand for methylene chloride, chloroform and "tetra", all products of the chlorination of methane were welcome. Today synthesis of glycerol would start from propene, via epichlorhydrine. But I agree that there is no demand for synthetic glycerol now. There is too much peace and biodiesel around :=) $\endgroup$ – Georg Dec 22 '14 at 16:19

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