[swissTemples]

I have a sulphated compound that rapidly hydrolyzes into a different form on contact with water (minoxidil sulphate). I found this problematic info in a study paper on pubmed.

Unfortunately I need to have the original sulphated compound in a liquid vehicle. So here are my questions:

1. Does hydrolyzation only occur in water or can it occur in different liquids as well?
2. Is there a way to protect compounds from hydrolyzation?
3. Could a pure ethanol or dmi or dmso or acetone vehicle keep the compound in its original form?

Thank you very much for any hints.

[Corribus]

By definition, hydrolysis is the breaking down of something (lysis) by water (hydro). So yes, strictly speaking you need water present for a hydrolysis. In principle this would mean it cannot occur in other liquids, but insofar as there are usually trace amounts of water in other solvents unless specific methods have been used to remove it, hydrolysis or other water-based reactions can still happen. It will depend on how sensitive your substance is to this kind of reaction.

If you are concerned about reactivity with water, you can simply dry your solvent using an appropriate drying agent before dissolution. Or you can store your substance in a dessicator or other dry environment if you are concerned with atmospheric water. It might be more helpful if you described your problem in a little more detail.

Also, just be aware that some substances that react with water can also react with alcohols as well, although the rate is usually slower. This may not be technically hydrolysis, in which water is actually added to the other reactant and consumed wholly in the process, but sometimes the term hydrolysis is used loosely to refer to any reaction with water. I'm not sure what the reaction is here, though, so I can't speculate further.

[racemiz.er]

By definition, hydrolysis is the breaking down of something (lysis) by water (hydro). So yes, strictly speaking you need water present for a hydrolysis. In principle this would mean it cannot occur in other liquids, but insofar as there are usually trace amounts of water in other solvents unless specific methods have been used to remove it, hydrolysis or other water-based reactions can still happen. It will depend on how sensitive your substance is to this kind of reaction.

Well I have this example, which we do in our chemical industry. We have a product which is an ethyl ester of a carboxylic. Speaking in terms of reaction, we actually hydrolyse it to a sodium salt in presence of sodium hydroxide, but actually this takes place in presence of methanol and dichloromethane! Strange! isn't it? To add to this, the moisture in the reaction mass only comes from the washing that has been done in the previous stage to the dichloromethane layer.

Chemistry can be strange in its ways! This makes it even more beautiful!

[kamiyu]

1) "suphated"?? I think you are referring to "sulphonated"

Sulphonation is reversible and SO3 group falls off in acidic aquesous environemtn

2) To protect from hydrolzyation I think there are basically two ways: i) Not to use water in reaction. 2) if water is inevitable, do not add acid and do not heat. SO3 group is fine at room temperature neutral water

[mjc123]

No, it's an ester of sulfuric acid, ROSO₂OH. Actually in this case the organic group is bound to the O via N:
http://www.sigmaaldrich.com/catalog/product/sigma/m7920?lang=en&region=GB
This looks as if it would be easily hydrolysed.