Sciencemadness Discussion Board

H2S reduction of ketones and aldehydes

EverythingAl2O3 - 16-6-2021 at 04:15

I found an interesting reduction reaction using H2S/H2S sources like Na2S. It is a photocatalytic reaction using a 5.5W low pressure mercury lamp and converts vicinal diols to ketones and ketones to alcohols at differing pHs.

One interesting thing stated in the procedure was saturating the solution with N2 gas. I have never seen a paper list saturating a solution with N2 only generating an N2 atmosphere.

Attachment: H2S reduction of ketones.pdf (885kB)
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symboom - 16-6-2021 at 05:54

Perfect timing just watched a video about making a hydrogen sulfide generator with candles and sulfur https://youtu.be/1hfC_ggJEhs

[Edited on 17-6-2021 by symboom]

EverythingAl2O3 - 16-6-2021 at 19:25


Quote:

Perfect timing just watched a video about making a hydrogen sulfide generator with candles and sulfur https://youtu.be/1hfC_ggJEhs

Yes I saw the same video and about 30 seconds in when he said "H2S is a reducing gas." I went "OMG HE'S RIGHT!!! How did I miss something so obvious?" and started searching for carbonyl reduction reactions.

[Edited on 17-6-2021 by EverythingAl2O3]

Swinfi2 - 17-6-2021 at 02:27

It's super easy to make H2S but god damn it stinks if you don't deal with it well. I went the paraffin + sulphur and heat route. Would not recommend. 1/10. It works but I'll be doing a different route next time I need H2S.

EverythingAl2O3 - 19-6-2021 at 06:43


Quote:

It's super easy to make H2S but god damn it stinks if you don't deal with it well. I went the paraffin + sulphur and heat route. Would not recommend. 1/10. It works but I'll be doing a different route next time I need H2S.

The paper listed Na2S as the source of H2S so maybe buying photography Na2S might be the way to go with this reduction reaction.

DraconicAcid - 19-6-2021 at 09:11

I've also seen old references to using H2S as a way to reduce nitro groups to amines. It strikes me as too much mucking around.