Hi all.
I am looking for ways to conversion methylene chloride to other useful compounds. Its cost is about $ 2 per 1kg.
1) Please could you suggest how and under what conditions is it possible to make the hydrolysis of Dichloromethane (DCM) in order to obtain useful
products from the reaction:
CH2Cl2 + H2O ---> CH2O + 2 HCl. Here we are getting dry hydrogen chloride.
I read somewhere about the hydrolysis is conducted at elevated temperatures. In the vapor phase? or perhaps to take place in the liquid phase, and
that the design of the device was simple.
What output can I expect?
2) Maybe there's a way to get the methanol from CH2Cl2 and CCl4? Even if not in one step (Its impossible to buy methanol here). Option CH2O reduction
could also be of interest.
[Edited on 17-4-2012 by Dronami_inc]ScienceSquirrel - 17-4-2012 at 04:28
Methylene chloride is very stable under most conditions. This is one of reasons for it's popularity as a solvent.
Really you are going to have to hit it with strong alkali at elevated temperatures and pressures to make a dent in it.Adas - 17-4-2012 at 10:40
NaOH can hydrolyze it to formaldehyde and NaCl.Nicodem - 17-4-2012 at 10:53
enough. Thank you. Unfortunately, it's not so easy as it seemed at first. Heard somewhere about reduction of dichloromethane to CH3Cl (useful) or CH4
(useless) with iron filings and hydrochloric acid(?)Nicodem - 23-4-2012 at 09:27
Actually, that is not enough at all. All that link gives is a couple of model equations for the SN2 and E2 steps of a hydrolysis reaction of CH2Cl2
for educational purposes. It does not give references to any such preparative reaction that would use hydroxides. I can give you references for the
hydrolysis of dichloromethane to formaldehyde with steam at several hundreds °C, but that is not what we are discussing here. Finding examples of
such a hydrolysis in solution by using hydroxides like you suggested is not that easy.
Next time, when you have some unreferenced ideas, make sure you search for the reference before you post suggestions. What appears obvious to
you, might appear such only because you lack the knowledge to understand why it is faulty. That's why scientist are supposed to use the scientific
method when building hypotheses - because they know not what is it they do not know. In the education, teachers use the educational method which can
be just the opposite - teachers know what the student does not know, so it does no harm to present concepts which are total bullshit from the
perspective of the scientific method (that's why textbooks don't have references!).AndersHoveland - 23-4-2012 at 15:48
Methylene chloride can indeed hydrolyse with water. But the reaction rate is so slow as to be neglibible, so there essentially is not any reaction
under ordinary conditions.
Refluxing (heating) with a base can increase the reaction rate (probably taking a few hours), but the base itself will cause degredation of the CH2O
as fast as it forms (Cannizzaro reaction)
For further reading about how the chlorine atoms in an organic compound can be substituted off more readily, using a complexed CuI catalyst (and
heating for 24 hours), see
"Copper-Catalyzed Halogen Exchange in Aryl Halides: An Aromatic. Finkelstein Reaction." Artis Klapars and Stephen L. Buchwald www.sciencemadness.org/talk/files.php?pid=7109&aid=96Sim...
