Author Topic: Short Questions Thread  (Read 10820 times)

Vesp

  • Administrator
  • Foundress Queen
  • *****
  • Posts: 3,130
Re: Short Questions Thread
« Reply #1120 on: February 22, 2012, 06:34:18 AM »
In the synth for benzyl chloride by doucherman,  it. says to use a 600w halogen lamp with the uv screen removed.  Is this because the uv rays affect the reaction?  If so, could a high powered uv flashlight (the kind used to detect flourescent dye in refrigeration systems) be used instead.  I known that the concentration of uv rays from this source is greater, and the heat produced by it. is significantly less  making it. less of a fire hazard.

I think a certain length of UV light is also recommended - I am not sure, but I think their is a lot of discussion about it over at sciencemadness. The UV light source you have may or may not offer the correct wavelength or something? Sunlight works, so if it were possible to do outside, you may want to consider..


The benzyl alcohol + HCl method sounds much better though!
Bitcoin address: 1FVrHdXJBr6Z9uhtiQKy4g7c7yHtGKjyLy

zgoat65

  • Subordinate Wasp
  • ***
  • Posts: 103
Re: Short Questions Thread: reference request
« Reply #1121 on: February 28, 2012, 02:15:29 AM »
Can anyone access this document?  It will only allows me to view the first page.  Here's a link to it:  http://pubs.acs.org/doi/abs/10.1021/ja02262a014?prevSearch=Halogenation%2Bof%2Bcinnamyl%2Balcohol%2Bhydrochloric%2Bacid&searchHistoryKey= 

I would greatly appreciate any help.
If you build a man a fire, he'll be warm for a day.
If you set a man on fire, he'll be warm for the rest of his life

RoidRage

  • Dominant Queen
  • ****
  • Posts: 386
Re: Short Questions Thread
« Reply #1122 on: February 28, 2012, 03:32:33 AM »
Can anyone access this document?  It will only allows me to view the first page.  Here's a link to it:  http://pubs.acs.org/doi/abs/10.1021/ja02262a014?prevSearch=Halogenation%2Bof%2Bcinnamyl%2Balcohol%2Bhydrochloric%2Bacid&searchHistoryKey= 

I would greatly appreciate any help.

Here it is:


THE REACTION BETWEEN ALCOHOLS AND AQUEOUS SOLUTIONS OF HYDROCHLORIC AND HYDROBROMIC ACIDS

James F. Norris, Muriel Watt, Ruth Thomas
J. Am. Chem. Soc., 1916, 38 (5), pp 1071–1079
DOI: 10.1021/ja02262a014

By the way, we have a references section for those requests but I think it's hidden to new members until they hits X posts (5, 10?, not too sure)

newbiechem

  • Pupae
  • **
  • Posts: 62
Re: Short Questions Thread
« Reply #1123 on: March 02, 2012, 04:31:44 AM »
something simple,  rhodium shows a MDA reaction given by Crossley and Moore using formic acid, formamide and  ketone....low yields 40%

could the leuckard be run whithout the formic acid with aqueous GAA?
this is from the old hive...(i didnt had the 00-02 posts) only the early ones.

"psyloxy
(Hive Bee)
10-20-00 01:51
No 61613
                  Re: Leukard scaleable ?
(Rated as: good read)     Bookmark     

This is something you might be intrested, a variation of the Leuckart, that doesn't even use formic acid and has yields reported as high as 70%

"The setup used is the same as in fig. 12(remember no vacuum!). and into the rxn flask is placed 275ml formamide, 80g MDP2P and 55ml of 9% glacial acetic acid (50ml dH2O + 5ml GAA) This is slowly heated to 140-150°C in the oil bath and kept there for 5 hours. The lower the temperature at which a sustained reaction (bubbling) can occur the better. Suffice to say that 150°C should not be passed. Very early on the water and AcOH will have distilled over and can be discarded.

After 5 hours the reaction is stopped and the flask cooled. The formyl-MDA can be isolated and hydrolized by any of the ways Strike just mentioned a few paragraphs back, but this method offers a third, very convenient way which should be tried. What the chemist does is forget about letting the flask and its contents cool. Instead, she removes the oil bath, places the flask back on the stirplate (distillation setup still attached), attaches  a vacuum and distills off all the formamide. What remains is a dark, heavy formyl-MDA precipitate that is allowed to cool down while the chemist makes up a solution of 150g KOH, 500ml EtOH and 125ml dH2O. This solution is poured into the formyl-MDA residue, the condenser from the distillation set is plopped in vertically and the solution refluxed for a mere 30 minutes. The solution is then acidified with concentrated HCl solution, the distillation setup reattached and all the ethanol distilled off under vacuum. What is left is MDA and aquaeous HCl and from this the MDA is liberated, as usual, by basifying with NaOH, extracting with solvent, drying the solvent and distilling to get MDA in 70% yield."

figure 12 shows just a simple distillation setup in an oilbath on a stir/hotplate.

--psyloxy-- Yeah mdma is funny but has anyone ever experienced ayahuasca ?    
   



does this follow up? would work?  yields would still be around 40% or i this wont even work and i should be ashamed of even asking this question? hahaha

thanks
« Last Edit: March 02, 2012, 04:53:51 AM by novicebrchem »

lugh

  • Global Moderator
  • Foundress Queen
  • *****
  • Posts: 876
Re: Short Questions Thread
« Reply #1124 on: March 02, 2012, 05:09:45 AM »
Quote
could the leuckard be run whithout the formic acid with aqueous GAA?

Your question was answered later on in that very thread:

Posts 1 - 15 of 15

       
       
        6ULdv8
      (Stranger)
      10-18-00 09:45
      No 61119
           Leukard scaleable ? 
       
      Hey there people. SWIM has dreamed of using the Leukart process a few
      times now and is had success (40-50 % each time). This dream has been
      acording to that outlined in Vogels (using formamide, formic and mdp2p).
      The amounts aminated did not exceed 100g mdp2p. Could someone of the know,
      please let me know if this process can be scaled up indefinately without
      impacting on yields. Also if anyone has any tips on increasing the yield,
      I would love to hear them.
      Thanks. 
       
       
       
        Antibody2
      (Hive Bee)
      10-18-00 10:14
      No 61127
           Re: Leukard scaleable ? 
       
      Look on the old boards for LabTop Huge Scale leukart. He was well into the
      kg quantities if I remember. With yields comparable to those you state.

      Jimi loves ya 
       
       
       
        psyloxy
      (Hive Bee)
      10-18-00 13:09
      No 61156
           Re: Leukard scaleable ?   Reply 
       
      http://rhodium.lycaeum.org/chemistry/leuckart.txt:

      "150 L MDP2P + 400 L NMF + 75 L Formic acid "

      is that enough ??

      --psyloxy-- 
       
       
       
        6ULdv8
      (Stranger)
      10-18-00 20:47
      No 61247
           Re: Leukard scaleable ? 
       
      Thanks for the replys. I cant believe i didnt find those articles. I think
      150l mdp2p might just be big enough .Has anyone actually had success using
      the microwave route , André Loupy et al, Tetr. Lett. 37(45), p 8177-80
      (1996)? I would love to dream of this method, anyone got a 60w monomode
      microwave lying around that i can borrow ? hehe 
       
       
       
        Dope_Amine
      (Hive Bee / Eraser)
      10-19-00 02:49
      No 61376
           Re: Leukard scaleable ?   
       
      The leukart is definately scale-able up to the multi kilo levels.  The key
      to high yields is having a much longer (1 week), gentler reaction.  Or, so
      I hear from the Europeans..

      something for your mind....... 
       
       
       
        6ULdv8
      (Stranger)
      10-19-00 04:21
      No 61406
           Re: Leukard scaleable ?   
       
      Dope_Amine..thanks heaps for the tip. I am going to dream up some more
      mdp2p this weekend then i will run a few leuckarts of varying sizes with
      increased reaction times. I will post the results. 
       
       
       
        psyloxy
      (Hive Bee)
      10-19-00 19:51
      No 61613
           Re: Leukard scaleable ? 
       
      This is something you might be intrested, a variation of the Leuckart,
      that doesn't even use formic acid and has yields reported as high as 70%

      "The setup used is the same as in fig. 12(remember no vacuum!). and into
      the rxn flask is placed 275ml formamide, 80g MDP2P and 55ml of 9% glacial
      acetic acid (50ml dH2O + 5ml GAA) This is slowly heated to 140-150°C in
      the oil bath and kept there for 5 hours. The lower the temperature at
      which a sustained reaction (bubbling) can occur the better. Suffice to say
      that 150°C should not be passed. Very early on the water and AcOH will
      have distilled over and can be discarded.

      After 5 hours the reaction is stopped and the flask cooled. The formyl-MDA
      can be isolated and hydrolized by any of the ways Strike just mentioned a
      few paragraphs back, but this method offers a third, very convenient way
      which should be tried. What the chemist does is forget about letting the
      flask and its contents cool. Instead, she removes the oil bath, places the
      flask back on the stirplate (distillation setup still attached), attaches 
      a vacuum and distills off all the formamide. What remains is a dark, heavy
      formyl-MDA precipitate that is allowed to cool down while the chemist
      makes up a solution of 150g KOH, 500ml EtOH and 125ml dH2O. This solution
      is poured into the formyl-MDA residue, the condenser from the distillation
      set is plopped in vertically and the solution refluxed for a mere 30
      minutes. The solution is then acidified with concentrated HCl solution,
      the distillation setup reattached and all the ethanol distilled off under
      vacuum. What is left is MDA and aquaeous HCl and from this the MDA is
      liberated, as usual, by basifying with NaOH, extracting with solvent,
      drying the solvent and distilling to get MDA in 70% yield."

      figure 12 shows just a simple distillation setup in an oilbath on a
      stir/hotplate.

      --psyloxy-- Yeah mdma is funny but has anyone ever experienced ayahuasca ?
       
       
       
       
        6ULdv8
      (Stranger)
      10-19-00 21:32
      No 61649
           Re: Leukard scaleable ?     
       
      psyloxy: wow thanks ! this method sounds great (never thought one could
      get anywhere near 70% yield with leukart).If this variation works out and
      is scale-able, i will be a real happy camper The leukart is so much easier
      than many of the other methods, i dont know why more people dont use it. 
       
       
       
        psyloxy
      (Hive Bee)
      10-20-00 06:29
      No 61769
           Re: Leukard scaleable ?   
       
      At the beginning the Leuckart rxn produced mainly tar and maybe 20%
      goodies, that's why the older bees don't like/perform it. BTW if I had
      access to NaBH4 I,too, wouldn't bother with it.

      --psyloxy-- Yeah mdma is funny but has anyone of you ever experienced
      ayahuasca ?

       
       
       
       
        Antibody2
      (Hive Bee)
      10-25-00 15:15
      No 63253
           Re: Leukard scaleable ?   
       
      Dope amine - that makes some sense, RC claimed a 36g product from 40g
      ketone using leukart w/ formic and formamide. and he let it go alot longer
      than 7 hours, 29 hours methinks.

      What exactly did you hear regarding "gentler reactions", be curious to
      know how much gentler.

      RC also mentioned maintaining PH at 4.5. Wonder what reference that came
      from? Anybee know?

      Jimi loves ya 
       
       
       
        Dope_Amine
      (Hive Bee / Eraser)
      10-26-00 23:15
      No 63765
           Re: Leukard scaleable ? 
       
      Sorry, I didn't notice your reply 'till now.  I don't know about the pH
      thingy. Best reaction temp.= 135-140 (barely bubbling) for 3 dayz. Good
      luck.

      something for your mind....... 
       
       
       
        LaBTop
      (Daddy)
      10-27-00 03:12
      No 63840
           Re: Leukard scaleable ? 
       
      Yep, highest temp would be 160 C, not the 190 C mentioned in my thread,
      there must have been something wrong with that digital thermometer those
      times. Medium bubbling will be seen at that temp. LT/

      WISDOMwillWIN 
       
       
       
        Antibody2
      (Hive Bee)
      10-27-00 09:29
      No 63915
           Re: Leukard scaleable ?   
       
      3 days, no kidding, what kind of yields are being realized tbhis way? What
      do you think LabTop? About this route compared to NaBH4 if an amphetamine
      is what is desired NOT a methamphetamine.

      Yeilds seem about the same.

      Jimi loves ya 
       
       
       
        Vibrating_Lights
      (Hive Bee)
      01-17-02 15:27
      No 257641
           Re: Leukard scaleable ? 
       
      Could the formamide be replaced with acetiamide for the same results.  Or
      is formic liberated when the amide condenses with the ketone reducing O
      which i am assuminng that acetic will not. But then again why fuc karound
      withthat when hydroxlamine will do the same trick in al/Hg.
      vL_ 
       
       
       
        terbium
      (Old P2P Cook)
      01-17-02 22:19
      No 257798
           Re: Leukard scaleable ?   
       
      Could the formamide be replaced with acetiamide for the same results.
      No. The formic acid moeity is specifically required since it is the
      reducing agent in the reaction.


and it's been translated in:

http://127.0.0.1/talk/index.php/topic,855

 8)
Chemistry is our Covalent Bond

Vesp

  • Administrator
  • Foundress Queen
  • *****
  • Posts: 3,130
Re: Short Questions Thread
« Reply #1125 on: March 13, 2012, 06:30:09 AM »
Due to the length of this short questions thread, I have made a new one: http://127.0.0.1/talk/index.php/topic,2962.0.html

Feel free to post your unanswered questions in the new thread! :) Same rules, same thing, etc...
Bitcoin address: 1FVrHdXJBr6Z9uhtiQKy4g7c7yHtGKjyLy