Okay first question: If one were to reflux NaOH with some 1,4-dichlorobenzene, available as non-napthalene mothballs, would it become 1,4-benzenediol? Second question, any way to change that 1,4- to 1,3-?

It won't work.

Okay. Care to explain why not? I think I've seen similar things referenced before..

i cant see why the dichlorobenzene to benzinediol wont work, but converting it from 1, 4 to 1, 3 will be highly impractical / impossible
as it would involve breaking and reforming 2 bonds, that have no good reason to break, you'd be much better off trying to find some 1, 3 dichlorobenzene.

Yeah I had figured that about going to the 1,3-, doesn't hurt to ask though

Ok, found this:

Dichlorobenzenes belong to the group of organic halogen compounds replacing two hydrogen atoms in benzene by chlorine atoms. There are three isomers; ortho-dichlorobenzene, colorless liquid boiling at 180 C, used as a solvent and chemical intermediate for dyes, pigment, agrochemicals and wide range of organic synthesis ; meta- , colorless liquid boiling at 172 C, used as a solvent and chemical intermediate; para- , white solid with a with a characteristic penetrating odor. It is used mainly as an insecticidal fumigant against moths, as a space deodorizer, as a general insecticide and fungicide on crops, and as a chemical intermediate for plastics, dyes, pharmaceuticals and other organic compounds. All they are insoluble in water and denser than water. They are prepared by the chlorination reaction of benzene in the presence of iron(III) chloride. (the chlorination under strong illumination and without iron(III) chloride leads to benzene hexachloride instead of mono or polychlorobenzenes). The chlorination reaction leads to similar ratio of ortho- and para-dichlorobenzene, but small amount of the meta isomer is performed. The ortho and para isomers are separated by fractional freezing. While the para isomer crystallizes, the ortho isomer remains liquid. The meta-dichlorobenzene is prepared by heating and pressure with aluminum chloride.


Does anyone know where I can find specifics about the heat+pressure+AlCl3 method, or know if theres a name for it?

Mega, wheres that OTC benzene you were talking about awhile back? :P

The reaction won't work because the two chlorines strongly deactivate the molecule. Believe me, I've tried this before. Doesn't work. If you can achieve higher pressure and temperature (i.e. in an autoclave) it quite likely could work, but I don't have an autoclave.

Any idea of what kind of pressure/temp might be needed?

Or would NaNO2 react with it at all?

I believe CuCl can be used to make chlorobenzene (and para-dichlorobenzene, I assume) reactive enough for nucleophilic substitution to be performed with relative ease. It probably makes the Cl bonded to the benzene ring into a superior leaving group. The increased reactivity of iodobenzenes and bromobenzenes, relative to chlorobenzene and fluorobenzene, is largely due to iodine and bromine being superior leaving groups to chlorine and fluorine. Nucleophilic substitution of halogens on benzene rings will proceed much more easily when there's a nitro group bonded to the benzene ring - and assuming you're after a nitrated product, you might want to try initially mononitrating the para-dichlorobenzene (it definitely won't be easy, though, because of the deactivating chlorines).

This is a hard chemical to utilize, after all its tough getting rid of halogenated hydrocarbons in the environment. For example DDT Not many ways to get rid of the chlorine, but it can be done under the right conditions.

Well today I went snooping in some cleaning storeroom in some public toilet. I found this stuff called De-odo-air. Its quoted on the label to be 99% diclorobenzene and from the post above I now know its para-dcb.

Anyway it was in some 20kg tub and was made by : (either of these two names due to my dodge memory); Modern Chemical Company, or, Modern Cleaning Company and it came from Aust.

Hope thats helpfull as a potential source if anyone finds a decent use for it. As yet I have made no enquires about possible uses or prices but ill keep you all posted when I find some.

Well, if you can deal with the 1,4-dichlorobenzene then by all means disregard this...

However, I just spent a good deal of time researching some pathways and came up with a fairly simple route to 1,3-diaminobenzene. Now, I know for a fact that refluxing this with HCl at 180C leads you to resorcinol (1,3-dihydroxybenzene), and I am almost 100% sure that I saw a quick reaction leading to 1,3-dichlorobenzene as well. I will have to go back and take a look at the database to find out what conditions and such. If you are still interested I'll check it out next time I can...

Although I suppose I would also have to explain the entire route to 1,3 diaminobenzene (from napthalene) as well and you may not be able to follow it all the way through....

Anyway, let me know.

Couldn't find much on nucleophilic substitution on benzene halides in my chem book, but IMO those two chlorines in 1,4-dichlorobenzene should help together to withdraw electrons from benzene and make it more positive. So that at least one Cl should be replaced with OH (at relatively normal conditions, no high pressure etc..)
Only similar reaction I could find in basic chem book was substitution of Cl in chlorobenzene by NH2-

The reaction won't work because the two chlorines strongly deactivate the molecule.

Deactivate toward electrophilic substitution, yes.. but opposite, toward nucleophilic..

It is not difficult to replace a halogen with OH by refluxing in a strong base. However, once you append the OH you will never get the O off again, at least I haven't seen any lab methods of doing so.

That bit about substituting a halogen for an amine is nasty stuff, the reaction proceeds with a metal amide in liquid ammonia. Liquid ammonia is not the kind of thing most home experimenters should be playing around with if they value their health.

There is a lab method of going from phenol to aniline but it uses some exotic catalysts and I do not believe thre is a very good yeild. Perhaps it was something like a zeolite catalyst? I might be wrong...it was a couple weeks ago that I found out about the method. Difficult and most likely impossible for the home-experimenter but possible...perhaps it was silicon dioxide with something else in the catalyst.

The only other way is to do it at some ridiculously high pressure for a looooong time.