03-31-03 02:43
No 422688
toluene oxidized with KMnO4 to benzoic acid
slake lime (CaOH) heated in a test tube till no more
water vapour comes off (idea here is to turn it into
CaO at around 1000 C)
mix slake lime with NaOH to make soda lime
then reflux benzoic acid with slake lime to do a decarboxalization
benzene :)
this has not been tried yet but will be done soon so dont take it as gospile
e3500 console login: root
bash-2.05#
(Newbee)
03-31-03 03:08
No 422693
Bee very careful around benzene; it is a carcinogen!
(Hive Addict)
03-31-03 04:06
No 422705
wasn´t tried.
there are at least three threads on benzene from toluene or benzoic acid.
and if you had read them you would know whats up.
also lot´s of fun by heating your testtube to 1000°C.
also it is complete undeserved: look for the member "halfapint" and "benzene".
[insert insults and offenses by personal taste here and feel insulted and offended - thanks]
ORG
(Distinctive Doe)
03-31-03 09:09
No 422789
Benzoic acid is easily available.
(Hive Addict)
03-31-03 18:08
No 422904
except Iraq, FoxyX?
and the availability of benzoic acid changes nothing on the problems to convert it to benzene.
Btw. the german patents you named in the thread on benzene (Henkel) are not on benzoic acid to benzene but Terephthalsäure from Phthalsäure.
ORG
(Master Searcher)
04-01-03 04:25
No 422989
Post 399163 (Aurelius: "Preparation of Methane (PolytheneSam's pic transc)", Methods Discourse)
Post 108611 (dormouse: "methylamine via glycine(Amino acid) (Page 1) -hellman", Novel Discourse)
http://www.geocities.com/dritte123/PSPF.
The hardest thing to explain is the obvious
(Hive Addict)
04-01-03 12:52
No 423097
Can be made via decarboxylation, pyridine from nicotinic acid is another example of this.
(Hive Bee)
04-02-03 23:06
No 423508
hmm other than that mistake seems pritty solid to me
and as far as heating test tubes to 1000 C done it many times
as I said this has not been practiced but it will work
I cant be fucked digging up refs but I didont pull it out
of my arse.
been making CaO from Ca(OH)2 for the last two weeks for
isomerizing you know what and no probs so far just heat
the test tube till its glowen red and no more steem comes
out of the tube.
but if you dont belive me like I care have a great day
practice makes perfect.
e3500 console login: root
bash-2.05#
(Hive Addict)
04-03-03 00:30
No 423523
Heating glass is an art it's all in the rate of heating that determines if it will shatter or just expand, I was looking into how these decarboxylations work this is a summary.
The calium oxide forms a salt with the carboxylic acid.
when you heat the shit out of that salt in the prescence of a little water, water reacts with this salt and forms an
alkaine-earth metal bicarbonate and your decarboxylated material.
(Hive Addict)
04-03-03 04:30
No 423556
Post 305141 (halfapint: "Decarboxylating Benzoic", Chemistry Discourse)
a reverse Friedel-Craft alkylation would be favourable I believe.
(Al foil and iodine with a reasonable column)
all I told - and it´s true - is that what you suggest isn´t new to the world and not to the HIVE and by now way a present or special at all.
I also think it is a not very recommended way for several reasons.
but show me I am wrong, I am awaiting your writeup in producing >100gram batches benzene this way.
until then
have a nice day
(Hive Bee)
04-03-03 22:30
No 423788
sorry I took it the wrong way .
ill be giving it a go soon I just need to get some
safety equipment I have had a few pms telling me how evil
benzene is :(
so better be safe than sorry.
this would be a perfect way to start an otc manganese acetate, acetone reaction to p2p :)
anyway till the next time the best to you all
e3500 console login: root
bash-2.05#
(Distinctive Doe)
04-04-03 11:29
No 423907
how can something that smells so good bee so bad
(Hive Addict)
04-04-03 20:42
No 424007
how can something that smells so good bee so bad
as someone who had so much depth can get so shallow too.
(Stranger)
04-12-03 13:29
No 426132
JACS volume 50 page 571 (1928)
A Preparation Method for Benzophenone
It is well known that simple carboxylic acids yield hydrocarbons to a greater or less extent when they are heated with finely divided metals, particularly copper and nickel.
In the case of aliphatic acids the reaction is usually difficult to effect. Acetic acid, for example, when heated with copper at 390-411°, gives mainly acetone and when nickel is used as the catalyst a considerable portion of the acid is decomposed into complex carbonaceous substances1. With aromatic acids the decomposition is usually easier but frequently, as with benzoic acid and nickel2, the reaction temperature is so high that the resulting hydrocarbons are largely transformed into other substances.
It has been found that this process of eliminating carbon dioxide from an acid can be used to advantage in the preparation of benzophenone from o-benzoylbenzoic acid.
The yields, 80-90% of the theoretical, exceed the average of those obtained by the Friedel and Crafts synthesis, in which benzene and benzoyl chloride react in the presence of aluminum chloride, by about 10 %. Furthermore o-benzoylbenzoic acid which is the intermediate in the synthetic anthraquinone process, is manufactured on a large scale and should be obtained without difficulty. It can also be prepared easily and inexpensively from phthalic anhydride, benzene and aluminum chloride3. This reaction goes nearly to completion, 95-97%, so that the yield of benzophenone based on the phthalic anhydride is still somewhat better than that obtained when benzoyl chloride and benzene are used, and the cost of the materials is much less.
When o-benzoylbenzoic acid is heated alone to about 300° some carbon dioxide is eliminated and benzophenone can be detected among the products. The yield, however is negligible. The catalysts which accelerate the reaction most efficiently are metals such as copper, nickel, iron and the o-benzoylbenzoic acid salts of these metals. It is not necessary that the metals be particularly finely divided as they go into solution in the acid, and the only apparent advantage in having a fine state of subdivision is to increase the rate of solution. The preferred catalysts are finely divided copper and the copper salt of o-benzoylbenzoic acid. The later is easily made by adding a copper sulfate solution to a solution of the sodium salt of the acid, washing, filtering and drying the precipitate at 110°. The velocity of the reaction increases with the amount of catalyst used, but too large a quantity causes inconvenience in getting out the product. It has been found that a satisfactory ratio is 1-3 g. of copper, or an amount of the copper salt of o-benzoylbenzoic acid containing an equivalent weight of copper, to 100 g. of the acid. In the presence of these catalysts carbon dioxide elimination begins at about 150° and increases as the temperature rises until 306° is reached, when the reaction mixture begins to boil. The speed of the reaction below 200° is too slow for practical purposes and above 280° there is decomposition, the formation of anthraquinone and unidentified tarry substances. The optimum temperature range is about 250-270°.
Three hundred grams of pure o-benzoylbenzoic acid was placed in a distilling flask with a low side tube. To this was added 20 g. of the copper salt of the acid. The flask was fitted with a mechanical stirrer arranged through a mercury seal, and a thermometer the bulb of which was immersed in the liquid when the material melted. The mixture was heated with stirring; carbon dioxide evolution was appreciable at 200°, and it was allowed to escape through the side tube of the flask and to bubble through water, which gave an indication of the progress of the reaction. The temperature was allowed to rise and was maintained at 260° until carbon dioxide evolution ceased (about four hours). It is necessary to continue until the carbon dioxide evolution has completely stopped. If a distillation is attempted before this point, a considerable quantity of anthraquinone is formed, which contaminates the product. The stirrer was taken from the flask, a short air condenser attached to the side tube and the thermometer raised out of the liquid as for distillation. The crude benzophenone was distilled over until the drops of distillate became dark in color; the weight of this crude product was 209 g., 86.6 % of the theoretical. One crystallization from 95% alcohol gave pure benzophenone, m. p. 47-48°, in an amount corresponding to 82-84% of the theoretical based on the o-benzoylbenzoic acid. The crystallization may be replaced by distillation in a vacuum.
1 Sabatier and Senderens, Ann. chim. phys., [8] 4, 467 (1905).
2 Sabatier and Mailhe, Compt. rend., 159, 217 (1914).
3 Cain, “The Manufacture of Intermediate Products for Dyes,” Macmillan and Co., London, 1918, p. 240
(Distinctive Doe)
04-12-03 15:17
No 426159
You should title your post like this ^^^ so that people useing the search engine can find the information easier.
See above post for info.
Just a friendly reminder.
(Stranger)
04-12-03 15:27
No 426162
The main point is decarboxylation of carboxylic acids in the presence of Cu or Ni or their salts. What can you use benzophenone for?
(Stranger)
04-12-03 17:18
No 426186
JACS volume 50 page 571 (1928) is listed as a reference in the Canadian Journal of Chemistry (Can. J. Chem.) volume 40 page 559 (1962).
Can. J. Chem. 40, 559 (1962) and Can. J. Chem. 42, 1235 (1964) both discuss decarboxylation of indole-2(and 3)-carboxylic acids using copper, copper salts, etc. in solvents, such as quinoline and N,N-dimethylacetamide. Note halfapint's post Post 305141 (halfapint: "Decarboxylating Benzoic", Chemistry Discourse)