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The Elk river spill II

Dear Reader,

When I looked at the case of the Elk river spill I considered the question of where does the 4-methyl 1-hydroxymethyl cyclohexane come from, it is not as if the aliens land in the car park and hand over drums of the chemical to the humans (who are glad to get it). Instead it is made by the chemical industry, one route would be from the reduction of dimethyl terephthalate using hydrogen, while in the lab chemists like to use expensive reagents such as lithium aluminium hydride in cheap glass flasks in the bulk chemical industry they like to use cheap reagents such as hydrogen in expensive metal reactors.

S. Richard Turner, Journal of Polymer Science Part A-Polymer Chemistry, 2004, volume 42, page 5847 explains how dimethyl terephthalate is hydrogenated using a palladium cataylst to make dimethyl 1,4-cyclohexanedicarboxylate which is then reduced using a copper / chromium catalyst to make 1,4-cyclohexanedimethanol. This type of catalyst is reported to have some ability to do a hydrodeoxygenation reaction on an alcohol. But the Cu/Cr system is more well known for the hydrogenation of carbonyls.

I suspect that if some acid is present then the 1,4-cyclohexanedimethanol will dehydrate to form an unsaturated monoalcohol which can be hydrogenated to form 4-methyl 1-hydroxymethyl cyclohexane.

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2 Responses

  1. Glad to see a reasoned discussion of the possible toxicity of 4-methyl-1-hydroxymethyl cyclohexane. The news media continue to stir up chemophobia without checking with anyone with chemical knowledge. My first reaction when seeing what chemical was involved in this case was that it did not look like anything I know to be toxic. I also checked the MSDS which I always look at as a legal document produced to avoid lawsuits. Bottom line I would not be worried about drinking water from this river. If it were dangerously toxic it would have shown up in the literature before this as it is almost certain that there have been accidental contacts in the production and handling of this compound before.

    • Thanks Jim,

      I feel encouraged, maybe I shouold write on the lack of relationship between how nice a taste / smell is and how toxic / otherwise harmful a substance is.

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