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Offline sjal

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Experimental
« on: February 22, 2018, 06:17:42 PM »
Hi everyone

To a conical flask containing (0.01 mole) of dibenzylidenecyloalkanones 1a or 1b and (0.02 mole) of chloroacetylchloride, dissolved in 60 ml of carbon disulphide, and then anhydrous aluminum chloride (0.04 mole) was added in small portions. The reaction mixture was stirred in an ice bath for 6 h, the carbon disulphide was evaporated and the residue was poured into cold hydrochloric acid; the yellow precipitate was collected by filtration, washed with excess water, then dried, and recrystallized from appropriate solvent.
 
1- how I can evaporated carbon disulphide?
2- how I can  pour the residue into cold hydrochloric acid?
THANK YOU :)
« Last Edit: February 22, 2018, 06:29:39 PM by Borek »

Offline Arkcon

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Re: Experimental
« Reply #1 on: February 22, 2018, 06:48:53 PM »
Greetings, sjal:, I'd like to welcome you and everyone new to the Chemical Forums,  but I want to ask you to review our Forum Rules{click}.  You already accepted the rules when you signed up for our forum, and you have to follow them, whether you agree with them or not, or even if you're unaware of them.

We're here to help you learn, and develop new skills.  But this isn't a cookbook chemistry site.  We don't do things just because they're cool.

Let's all work together with what you have, and look for what you need.

Hi everyone

To a conical flask containing (0.01 mole) of dibenzylidenecyloalkanones

I don't recognize this name, that's OK, different words are used in different countries.  If you used the IUPAC name, everyone would understand it.  Its an idea you could consider.

Quote
1a or 1b

So that somehow changes the definition of the past word?  How can we know what you mean?  Can you say it a different way?  If you can't, then why can't you?  Did you just copy this without understanding it?  Are you ready for previous and future steps, to keep yourself from getting hurt?  I have to wonder, I'm not sure.
Quote
and (0.02 mole) of chloroacetylchloride, dissolved in 60 ml of carbon disulphide, and then anhydrous aluminum chloride (0.04 mole) was added in small portions. The reaction mixture was stirred in an ice bath for 6 h, the carbon disulphide was evaporated and the residue was poured into cold hydrochloric acid; the yellow precipitate was collected by filtration, washed with excess water, then dried, and recrystallized from appropriate solvent.

Quote
1- how I can evaporated carbon disulphide?

What do you know about carbon disulfide's properties?  There are a number of options, but they should include a good fume hood.

Quote
2- how I can  pour the residue into cold hydrochloric acid?

What, exactly, would stop you?  Can you take a guess, how you would set this up, and how you would do it, and let us tell you if its a good one?  That's not a bad way to learn.

Quote
THANK YOU :)
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline wildfyr

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Re: Experimental
« Reply #2 on: February 22, 2018, 09:52:20 PM »
I've always felt like the boiling point of carbon disulfide was an anomaly. Its totally unexpected to me.

Offline sjal

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Re: Experimental
« Reply #3 on: February 23, 2018, 06:34:03 AM »

[size=0px]Did you just copy this without understanding it?  Are you ready for previous and future steps, to keep yourself from getting hurt?  I have to wonder, I'm not sure.[/size][/size][/color]

 i understand i will do the exprmental with diferant matrial... My Qustions was 1 and 2  which is again how i can evaporate the CS2.. and how i know its all evaporated?? and 2- how i pour the residue into cold HCl?

I know carbon disulfide evaporate at RT but i never evaporate it at lab so should i leave the conical in fume hood?? and for how long? how i know it evaporated all??



 Quote
2- how I can  pour the residue into cold hydrochloric acid?

What, exactly, would stop you?  Can you take a guess, how you would set this up, and how you would do it, and let us tell you if its a good one?  That's not a bad way to learn.


i never did pouring in the lab so that why am asking here??
should i just pout the residue in flask with HCl and what the mount of HCl.

Offline Arkcon

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Re: Experimental
« Reply #4 on: February 23, 2018, 07:56:41 AM »
sjal:, I've locked this thread, for now.  It soesn't seem, to me, that you have the very basics of the organic chemistry laboratory skills you need to work safely.  I'll defer to our organic chemistry experts, when they have a chance to review your raw materials and your process.  In the meantime, you can do some more reading, confer with your instructors or other experts in your lab, or work on a different explanation of your process.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline wildfyr

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Re: Experimental
« Reply #5 on: February 28, 2018, 04:46:11 PM »
sjal,
We discussed it among the experienced members of the forum and have decided you are not doing anything illicit, so we will try to help you.

The very first thing I would do is not use carbon disulfide. It is volatile, toxic, and has a low flashpoint. Dichloromethane is the typical solvent for this reaction (Freidel-Crafts acylation). It, and all your other reagents, should be thoroughly dried of water or else the reaction will likely fail or yield poorly. It should also be done under N2.

For adding HCl, I would do a liquid/liquid extraction of the reaction with something like 1M aqueous HCl solution. You can easily find examples of this technique on youtube. The dichloromethane can then be distilled off in a rotovap or a short-path distillation apparatus with vacuum or very mild heat.

Would you care to share with us your ultimate goal for this acylated dibenzylidene compound? The more info we have, the more we can help. Also if we know you're in an academic or industrial lab we can have a better concept of the resources and guidance available to you.

Offline pgk

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Re: Experimental
« Reply #6 on: March 01, 2018, 12:32:10 PM »
Please, be aware that:
1). Alkylidene cylolakanones have a ketone group that is conjugated with a double bond, which is an electron attracting group and therefore, an aromatic deactivator that means: meta- Friedel-Craft acylation, long reaction times and moderate yields.
2). Additionally, you have a molecularly symmetrical bis-alkylidene cylolakanone, which means that you will probably get a mixture of monoacylated and bis-acylated alkylidene cylolakanone that might be difficult to separate.
3). Furthermore, AlCl3 may also catalyse an ortho- electrophilic attack of the benzene ring to the conjugated double bond and finally lead to expansion of the benzene ring, via intermolecular isomerization.
4). Thus, it is better to describe the final product that you want and so, we can help you to prepare it by a more convenient synthetic route.
« Last Edit: March 01, 2018, 12:43:59 PM by pgk »

Offline wildfyr

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Re: Experimental
« Reply #7 on: March 01, 2018, 02:21:41 PM »
pgk, I think the goal is to diacylate it. 2 equivalents of chloroacetyl chloride are used. I also don't think this molecule is very deactivated, the ketone is several bonds away from the benzene ring even though its conjugated.

Offline pgk

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Re: Experimental
« Reply #8 on: March 01, 2018, 02:54:37 PM »
Ok, sjal try the Friedel-Craft bis-acylation in dichloromethane and keep us informed about the obtained results.
Good luck.

Offline sjal

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can i use acetyl chloride instead of chloroacetyl chloride?
« Reply #9 on: March 18, 2018, 09:23:47 PM »
Can i use acetyl chloride instead of chloroacetyl chloride?
I want to Synthesis of diarylidenecycloalkanones monomers..
(0.01 mole) of dibenzylidenecyloalkanones 1a or 1b and (0.02 mole) of chloroacetylchloride, dissolved in 60 ml of carbon disulphide, and then ALCL3 (0.04 mole) was added in small portions then will get yellow precipitate which will be reacted with thiourea...
Can I use acetyl chloride instead of chloroacetylchloride?

I Attach pic of the reaction...

Offline wildfyr

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Re: can i use acetyl chloride instead of chloroacetyl chloride?
« Reply #10 on: March 19, 2018, 12:16:11 AM »
You can but then you won't have a reactive handle for the thio urea.

Also it would be nice if you responded on your previous topic to some of our suggestions

Offline sjal

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Re: can i use acetyl chloride instead of chloroacetyl chloride?
« Reply #11 on: March 19, 2018, 03:26:33 PM »
You can but then you won't have a reactive handle for the thio urea.

Also it would be nice if you responded on your previous topic to some of our suggestions

thank you...
is there any suggestions  because i don't have the chloroacetyl chloride...


for the other topic i thought its locked ... i just see that it unlocked
thank you

Offline sjal

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Re: Experimental
« Reply #12 on: March 19, 2018, 03:29:03 PM »
sjal,
We discussed it among the experienced members of the forum and have decided you are not doing anything illicit, so we will try to help you.

The very first thing I would do is not use carbon disulfide. It is volatile, toxic, and has a low flashpoint. Dichloromethane is the typical solvent for this reaction (Freidel-Crafts acylation). It, and all your other reagents, should be thoroughly dried of water or else the reaction will likely fail or yield poorly. It should also be done under N2.

For adding HCl, I would do a liquid/liquid extraction of the reaction with something like 1M aqueous HCl solution. You can easily find examples of this technique on youtube. The dichloromethane can then be distilled off in a rotovap or a short-path distillation apparatus with vacuum or very mild heat.

Would you care to share with us your ultimate goal for this acylated dibenzylidene compound? The more info we have, the more we can help. Also if we know you're in an academic or industrial lab we can have a better concept of the resources and guidance available to you.

I did it using DCM under N2 but never workd

Thank you for your suggestions

Offline sjal

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Re: Experimental
« Reply #13 on: March 19, 2018, 03:30:16 PM »
Ok, sjal try the Friedel-Craft bis-acylation in dichloromethane and keep us informed about the obtained results.
Good luck.

did not work i got the starting again...
Thank you for your replay :)

Offline wildfyr

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Re: can i use acetyl chloride instead of chloroacetyl chloride?
« Reply #14 on: March 19, 2018, 04:58:45 PM »
Could you chlorinate chloroacetic acid? It won't be fun, but you really do need a haloacetyl halide reagent. Halogenating at the acetyl spot on your diarylidenecycloalkanones seems like it would be difficult to do cleanly.

Perhaps make it by using chloroacetic acid and excess PCl5, then distill the product off.

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