Author Topic: Benzal chloride  (Read 6154 times)

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flipper

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Benzal chloride
« on: April 28, 2002, 08:26:00 PM »
Does anybody know how too synthesize Benzal Chloride.
Before you start Flippin I've searched but haven't find anything.


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Elementary

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By
« Reply #1 on: April 28, 2002, 08:59:00 PM »
By bubbling chlorine gas into toluene with UV light.

First you get benzyl chloride, and then with further chlorination you get benzal chloride, then lastly you will get benzotrichloride.

C6H5.CH3 + Cl2 = HCl + C6H5.CH2Cl (Benzyl Chloride)
C6H5.CH2Cl + Cl2 = HCl + C6H5.CHCl2 (Benzal Chloride)
C6H5.CHCl2 + Cl2 = HCl + C6H5.CCl3 (Benzotrichloride)

The procedure will be the same as :

https://www.thevespiary.org/rhodium/Rhodium/chemistry/benzylchloride.html



Except that the boiling point of benzal chloride is 207°C, and this change to the procedure :

An alternative method of determining the completion of the reaction is to weigh the flask and toluene, and to stop the passage of chlorine when the increase in weight is 74 g.


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demorol

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Exact preparation
« Reply #2 on: April 28, 2002, 09:24:00 PM »
From Megalomania's Controversial Chem Lab:

http://roguesci.org/megalomania/



Benzal Chloride

Place 58mL (50g) of toluene in a round bottom 100mL flask. Attach a Clasien adapter to the flask. On the angled arm of the adapter, attach a condenser set up for refluxing. Since excess chlorine gas will be released from the top of the condenser, affix a one-holed stopper with a short length of glass tubing connected to a long hose, direct the hose to a well ventilated area. On the straight arm of the adapter, attach a length of glass tubing with a bubbler at the end that extends below the surface of the toluene. The top of this tube is connected to a chlorine generator.
     Position the setup such that the flask is in direct sunlight, or very strong light. Sunlight is superior. Heat the toluene to boiling while a current of dry chlorine gas is bubbled in, the chlorine can be dried by passing it through two drying bottles filled with concentrated sulfuric acid. The course of the reaction is best judged by weighing the product; the reaction is complete when the toluene has increased by 40g, the total weight being 90g. By weighing the flask beforehand, and periodically interrupting the flow of chlorine to cool and weigh the flask, the completeness of the reaction can be determined. Without weighing, it is very difficult to gauge this reaction as the length varies greatly.
     In the summer, in direct midday sunlight, the reaction is complete in a few hours. In winter, or low light, the reaction needs 12-24 hours to complete. Adding 4g of phosphorus pentachloride to the toluene can enhance the reaction. The crude benzal chloride thus obtained can be directly used to make benzaldehyde.


I assume that you need it for benzaldehyde synthesis, so I'll post it righ here. It is from the same site as benzal chloride preparation.

Benzaldehyde from Benzal Chloride

To prepare benzaldehyde, start with the crude benzal chloride obtained from its Synthesis. Into a round-bottomed flask with the benzal chloride, add a solution of 500mL of water and 150g of calcium carbonate. Set the flask up for reflux and heat for 4 hours on an oil bath. Keep the oil bath at 130° C by checking the oil itself with a thermometer.
     After refluxing, steam distill the product to obtain crude benzaldehyde oil. (The portion that did not distill over contains some benzoic acid. It can be discarded, or purified by filtering while hot through a piece of fluted filter paper, then adding concentrated HCl to the filtrate. On cooling the benzoic acid will precipitate, it is filtered and recrystallized from hot water.) The crude benzaldehyde oil is treated with a concentrated solution of sodium bisulfite, after shaking for a long time the oil should have dissolved into solution. If any crystals happen to form during the shaking, add water until they dissolve.
     After most of the oil is dissolved, filter the solution over fluted filter paper, and then treat the filtrate with sodium carbonate until it is strongly alkaline. This liquid is now steam distilled to obtain pure benzaldehyde. The product can be further purified by mixing with ether, letting the ether evaporate, and distilling (normal, not steam) the benzaldehyde.
     If you have obtained benzaldehyde from other sources, it must be purified if it is anything less than ACS grade. It should be washed with sodium carbonate solution, dried, and distilled with minimum atmospheric exposure. Only the fraction collected at 178-180° C is kept.



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Rhodium

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Nice Site Demorol!
« Reply #3 on: April 28, 2002, 11:18:00 PM »

The land beneath our feet, the air in our lungs, the trees on the horizon.
All are sources of chemicals.
No legislation can ban them, no government can control them, no soldier can take them.
If industry can do it, so can I.




alchemy_bee

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SWIM is planning on trying that synth.
« Reply #4 on: April 29, 2002, 04:34:00 AM »
SWIM is planning on trying that synth. What determines the amount of chlorination (1x,2x,or 3x)? Durration of exposure? For example is there any di or tri chlorinated products before the major componet is preceedingly chlorinated?

Do mirrors reflect UV light? SWIM is trying to be industrius and wants to chlorinate toluene on a large scale - 5 gallon water jugs in a field, each with chlorine gas feed, surrounded by a circle of large floor mirrors proped up to catch and focus the sunlight.

Input please, can to much UV help or hurt?

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flipper

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This looks good too isn't it
« Reply #5 on: April 29, 2002, 07:32:00 AM »
Benzaldehydes are produced by heating the corresponding benzal chloride containing less than 1% anhydrous ZnCl2 to above 100 DEG C. (preferably 105 DEG C.-135 DEG C.) and adding water at substantially the rate at which it reacts with the benzal chloride. In examples (1) benzaldehyde is obtained from benzal chloride and (2) o-chlorobenzaldehyde from o - chlorobenzalchloride, p-Chloro- and 2 : 6-dichloro-benzaldehydes, and o-, m- and p-tolualdehydes are also mentioned.

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(http://l2.espacenet.com/espacenet/viewer?PN=GB899953&CY=gb&LG=en&DB=EPD)

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Elementary

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UV light
« Reply #6 on: April 29, 2002, 02:08:00 PM »
Yes most ordinary mirrors reflect UV.

UV lamps and flouresent tubes can be bought from aquarium suppliers, disco suppliers, and also electrical component suppliers (UV PCB developing).

And how about a UV light bulb :


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alchemy_bee

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UV
« Reply #7 on: April 29, 2002, 04:20:00 PM »
Why bother with black lights though? I mean the sun is a powerful source and would probably produce the most efficient use of Cl2. I cant wait to see how my sun catcher idea works, i will get back with that.

Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

alchemy_bee

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OTC toluene
« Reply #8 on: April 30, 2002, 06:19:00 PM »
How is fractionated OTC toluene for this reaction? Its getting harder to find but i can still get it, im just wondering if fractionating it will seperated it enough from its other componets to make it usable for this.

Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

foxy2

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Comment
« Reply #9 on: April 30, 2002, 06:36:00 PM »
"Adding 4g of phosphorus pentachloride to the toluene can enhance the reaction."

Or a pinch of matchbox RP, this reaction can bee done with no UV in the same way by adding a catalytic amount of RedP.
I posted an abstract sometime ago.

Or you can use Lithium Hypochlorite and NO UV

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alchemy_bee

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bleaching powder
« Reply #10 on: April 30, 2002, 10:23:00 PM »
Foxy do you have a writup for Lithium hypochlorate? Rhod has a process on his site that uses bleaching powder but it isnt to specific. Thanks

Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

foxy2

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here
« Reply #11 on: April 30, 2002, 11:39:00 PM »
time to learn about tfse?

Post 36700

(CHEM_GUY: "Re: benzyl chloride from hypochlorite salts", Chemistry Discourse)

Post 101658 (missing)

(Scooby Doo: "Re: Benzyl Chloride", Chemistry Discourse)

Post 108293 (missing)

(dormouse: "benzyl chloride from toluene?  -drone 342", Novel Discourse)

Post 228452

(foxy2: "Re: Benzaldehyde -> Benzyl Chloride (cold)", Chemistry Discourse)



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alchemy_bee

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Oh you silly fox, yup did read all of thoes, i ...
« Reply #12 on: May 01, 2002, 03:19:00 AM »
Oh you silly fox, yup did read all of thoes, i have yet to find an article on lithium hypochlorate, i understand the the molar amounts would be the same for that reaction - but for the purpose of discusion it would be interesting to have seen the yield variations of different alkali metal hypochlorate chems.

Anyways the writup on Rhods site is exactly what all thoes posts indicate.  ;)

Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

alchemy_bee

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Benzyl Chloride cant be that suspisious to order ...
« Reply #13 on: May 01, 2002, 03:36:00 AM »
Benzyl Chloride cant be that suspisious to order from the right supplier.

Reasearched uses include manufacture of perfumes, dyes, synthetic tannins, artificial resins, photography, pesticides and gasoline gum inhibitors. If one found a company with specific areas of interest in supplying raw materals to any one of these industries one might have luck. any input?



Can a bee be visa vis its entity when half a bee philosophically must ipso facto half not be?

Elementary

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You wont get the right results using lithium ...
« Reply #14 on: May 01, 2002, 03:38:00 AM »
You wont get the right results using lithium hypochlorate, maybe you mean hypochlorite !

Lithium hypochlorite is well expensive compared to calcium or sodium hypochlorite anyway.

..........

Is it just a case of using more hypochlorite to achieve benzal chloride ?

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PrimoPyro

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List 2
« Reply #15 on: May 01, 2002, 04:31:00 AM »
Benzyl Chloride is list 2 in the US with few "common" uses, unlike toluene, which is also list 2. US bees should not order benzyl chloride from US suppliers in my opinion.

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Elementary

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Benzyl Chloride 2 Benzaldehyde
« Reply #16 on: May 01, 2002, 05:36:00 PM »
If the end product that you require is benzaldehyde then this can also be made from benzyl chloride :

Benzyl chloride is boiled under reflux for several hours with a solution of cupric nitrate or lead nitrate, when hydrolysis and oxidation occurs:

C6H5.CH2Cl + H2O = C6H5.CH2OH + HCl
C6H5.CH2OH + O = C6H5.CHO + H2O

A stream of carbon dioxide is usually passed through the mixture to remove oxides of nitrogen. The benzaldehyde is extracted with ether, dried with anhydrous calcium chloride, and distilled. If necessary it can be purified further by forming a crystalline addition compound with sodium bisulphite and distilling this with dilute sulphuric acid.

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Nemo_Tenetur

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watched in EU too
« Reply #17 on: May 01, 2002, 06:12:00 PM »
Although not explicitly scheduled in EU-Order 3677/90, it's a known amphetamine precursor and therefore watched in EU too. :(

Osmium

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This thread is a nice example of why spelling IS ...
« Reply #18 on: May 02, 2002, 09:18:00 AM »
This thread is a nice example of why spelling IS important!

chloride MCl
hypochloride MClO
hypochlorite (?) MClO2
hypochlorate doesn't exist
chlorate MClO3
perchlorate MClO4

I'm not fat just horizontally disproportionate.

PrimoPyro

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Spelling.......
« Reply #19 on: May 02, 2002, 04:43:00 PM »
chloride MCl
hypochloride MClO
hypochlorite (?) MClO2
hypochlorate doesn't exist
chlorate MClO3
perchlorate MClO4


And I assume you mean hypochlorite and chlorite, respectively, Os?  ;)

ClO- is hypochlorite, ClO2- is chlorite. I know you know this heh, so even you must make spelling errors from time to time.  :P

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Vivent Longtemps La Ruche!