Sciencemadness Discussion Board

Ethanol to chloroform

tahallium - 5-6-2020 at 12:16

So I did the haloform reaction to make chloroform before and it's really easy but the yield is TERRIBLE acetone is so expensive and using so much bleach isn't a good idea cuz chloroform is quite soluble
Can I make chloroform using ethanol?? I have two ideas:
Bubbling chlorine into ethanol to make chloral and adding water+sodium hydroxide to make chloral hydrate it'll hydrolyze immediately to chloroform and sodium chloride I think

Or use tcca, sodium dcca to make the haloform reaction using ETHANOL??
Please tell me if I'm wrong

Abromination - 5-6-2020 at 13:10

As far as I am aware, most people stick with the haloform reaction for the production of ethanol. In most places, both sodium and calcium hypochlorite as well as acetone are dead cheap. Chloroform doesn't find too many uses in labs today due to its toxicity and tendency to oxidize to phosgene under UV light and air exposure, so make sure to stabilize your product with 2% ethanol and keep it in an amber bottle covered in aluminium foil. Given this, it may be better to purchase an alternative solvent such as DCM for general use and prepare chloroform using the haloform reaction as needed.

Anyways, chloral hydrate does indeed react with a mole of sodium hydroxide to form chloroform as well as sodium formate and water (not NaCl). There is an extensive thread on the synthesis of chloral hydrate, including both the chlorination of ethanol as well as a method using trichloroethylene. It is worth a read, but shows how messy the chlorination is and how the trichloroethylene path is way more expensive than making chloroform out of a hypochlorite and acetone.
https://www.sciencemadness.org/whisper/viewthread.php?tid=25...
I don't see how ethanol would react with TCCA to form chloroform, and the haloform requires a ketone to be halogenated. Ethanol is not a ketone. Besides, the haloform takes place in basic medium, TCCA is an acid.

Ubya - 5-6-2020 at 13:28

Quote: Originally posted by Abromination  
As far as I am aware, most people stick with the haloform reaction for the production of ethanol. In most places, both sodium and calcium hypochlorite as well as acetone are dead cheap. Chloroform doesn't find too many uses in labs today due to its toxicity and tendency to oxidize to phosgene under UV light and air exposure, so make sure to stabilize your product with 2% ethanol and keep it in an amber bottle covered in aluminium foil. Given this, it may be better to purchase an alternative solvent such as DCM for general use and prepare chloroform using the haloform reaction as needed.

Anyways, chloral hydrate does indeed react with a mole of sodium hydroxide to form chloroform as well as sodium formate and water (not NaCl). There is an extensive thread on the synthesis of chloral hydrate, including both the chlorination of ethanol as well as a method using trichloroethylene. It is worth a read, but shows how messy the chlorination is and how the trichloroethylene path is way more expensive than making chloroform out of a hypochlorite and acetone.
https://www.sciencemadness.org/whisper/viewthread.php?tid=25...
I don't see how ethanol would react with TCCA to form chloroform, and the haloform requires a ketone to be halogenated. Ethanol is not a ketone. Besides, the haloform takes place in basic medium, TCCA is an acid.


ethanol gets oxidized to acetaldehyde, and that reacts again to form chloroform.

so you'll need double the amount of bleach for the same amount of product.

what you could do is make calcium hypoclorite (if you can't buy any) by running chlorine gas on moist calcium hydroxide, you can then use it as a more concentrated form of bleach

Abromination - 5-6-2020 at 14:16

Quote: Originally posted by Ubya  
Quote: Originally posted by Abromination  
As far as I am aware, most people stick with the haloform reaction for the production of ethanol. In most places, both sodium and calcium hypochlorite as well as acetone are dead cheap. Chloroform doesn't find too many uses in labs today due to its toxicity and tendency to oxidize to phosgene under UV light and air exposure, so make sure to stabilize your product with 2% ethanol and keep it in an amber bottle covered in aluminium foil. Given this, it may be better to purchase an alternative solvent such as DCM for general use and prepare chloroform using the haloform reaction as needed.

Anyways, chloral hydrate does indeed react with a mole of sodium hydroxide to form chloroform as well as sodium formate and water (not NaCl). There is an extensive thread on the synthesis of chloral hydrate, including both the chlorination of ethanol as well as a method using trichloroethylene. It is worth a read, but shows how messy the chlorination is and how the trichloroethylene path is way more expensive than making chloroform out of a hypochlorite and acetone.
https://www.sciencemadness.org/whisper/viewthread.php?tid=25...
I don't see how ethanol would react with TCCA to form chloroform, and the haloform requires a ketone to be halogenated. Ethanol is not a ketone. Besides, the haloform takes place in basic medium, TCCA is an acid.


ethanol gets oxidized to acetaldehyde, and that reacts again to form chloroform.

so you'll need double the amount of bleach for the same amount of product.

what you could do is make calcium hypoclorite (if you can't buy any) by running chlorine gas on moist calcium hydroxide, you can then use it as a more concentrated form of bleach

That would work, I think Vogel has some notes on the procedure. Basic haloform is still probably cheaper.

Ubya - 5-6-2020 at 14:31

i can buy 1L of acetone for 2 euros, and calcium hydroxide is impossible to find here, maybe for tahallium is still cheaper going a different route even if for us would be more work and more expensive

Pool Schock

MadHatter - 5-6-2020 at 19:52

This could work for you as some pool shocks
are calcium hypochlorite. Usually found with
other pool chlorinators such as TCCA.