08-19-00 00:55
No 42526
I recently came across a package of mothballs containing 99% p-dichlorobenzene in a supermarket. My immediate thought was to convert this to hydroquinone. Right now my options are:
1. NaOH, high pressure and 350c (not a very pleasant one, wich i dug from an old o-chem book)
2. NaOH and Cu powder(as in 5-bromovanillin to hydroxyvanillin in rhodiumīs site).
Iīm willing to try the second option as the first one is more dangerous and would require some carefull planing and contruction of an appropriate reaction vessel. but I feel i need some comments from you bees before i commit myself to this task. Any new ideas are greatly appreciated.
(Official Hive Translator)
10-16-01 15:03
No 225230
See this: Post 225229 (Antoncho: "Re: route from acetaminophen (paracetamol)", Chemistry Discourse)
Antoncho
(Hive Bee)
10-16-01 17:33
No 225270
Take care with nr. 1
Dioxine (Saveso you know) is made with chlorinated phenol, heath and NaOH
(Hive Bee)
10-16-01 17:58
No 225284
I wonder if formylation could be done first, followed by methoxylation? It seems to me there's a few specialized methods out there that work well on deactivated systems like this. Would formaldehyde and stannic chloride work?
(Stoni's sexual toy)
10-16-01 18:02
No 225287
SnCl4/H2CO only works on phenols.
(Distinctive Doe)
11-27-01 04:54
No 241074
Hydrolysis of aromatic halocompounds catalysed by zeolites.
Kucera, M.; Kralik, M.
Pet. Coal (1999), 41(2), 96-98.
CODEN: PCOAFI ISSN: 1335-1141. Journal in English. CAN 132:349228
Abstract
Liguid phase hydration of chlorobenzene, p-dichlorobenzene and o-, m-, p-chlorophenol over H-form mordenite and faujasite at 150-215° in a batch system was studied. Influence of the type of halocompounds and catalysts, reaction temp., the amt. of methanol in the reaction mixt. on the conversion of halocompounds, and selectivity to products formation was detd.
Do Your Part To Win The War
(Distinctive Doe)
11-27-01 06:34
No 241100
Preparation of hydroxy aromatic compounds from halogenated aromatic compounds.
US Patent 3413341
Abstract
Haloaromatic compds. are hydrolyzed in good yield in aq. medium with, preferably, Na or K acetate or propionate as hydrolyzing agent and Cu or Cu2O as catalyst at 200-350°, and at pH 3-6, under pressure sufficient to keep reactants in the liq. phase. Thus, in a 1 l. Cu-coated autoclave, a mixt. of 0.4 mole a-chloronaphthalene, 0.6 mole Na propionate, 1.13 mole EtCO2H, 500 ml. H2O, and 4 g. Cu2O was heated 7 hrs. at 275° with agitation and worked up to give 87% a-naphthol. This method gives a good yield irrespective of the no. and kind of halogen atoms to be replaced, and of other substituents on the aromatic nucleus; proceeds under milder conditions; forms fewer byproducts; and requires only .apprx.1 mole equiv. of OH ion for each halogen atom replaced. Yields above 90-5% may be obtained if unreacted and incompletely reacted material is recycled. A no. of examples were given to illustrate the method and study process variables for a range of halobenzenes and naphthalenes, esp. chlorotoluenes, chlorophenols, and dichlorobenzenes.
Do Your Part To Win The War
(Hive Addict)
11-28-01 07:26
No 241508
Hydroquinone is as OTC as it gets! Way cheeper than mothgonads.WHY BOTHER?