Sandmayer addition question

Discussion in 'Drug Chemistry' started by flippy202, Feb 24, 2011.

  1. flippy202

    flippy202 Member

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    In a forum farmer bob found the following,

    "In a 10 L 3 neck flask with a external stirrer were added 1030 g of GABA and 2300 mls of DH2O. Then to the same flask were added 690g of NaNO2. Next a pressure equalized funnel (not crucial but easier, or you can make one) was charged with 1150 ml of 35 % HCL. The HCL was slowly dripped (adjust it) to minimize the heat evolved and the brown gas! ( It took around one hour and a half to add)."

    Farmer bob finds this hard to believe the dripping of over 1l of 35% hcl was done in an hour and a half when usually farmer bob takes 4 hours to drip 340ml of 35%hcl into his reactions. is it possible that bob is wrong and doing it way too slow or is what the other poster saying way off base? ( he claims to get a total of 900g NaGhb)
     
  2. flippy202

    flippy202 Member

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    so no opinions on this one?
     
  3. porkstock41

    porkstock41 Every time across from me...not there!

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    i don't have that much experience, but i think dripping it more slowly would be better, not worse
     
  4. flippy202

    flippy202 Member

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    yes and bob does a third of what that guy posted and it takes him 5 hours. this guy does a whole liter in an hour and a half. i wonder if he is full of shit or not.
     
  5. porkstock41

    porkstock41 Every time across from me...not there!

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    well maybe he is, maybe he isn't, but i don't think it'd hurt to take longer
     
  6. Mr.Writer

    Mr.Writer Senior Member

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    you could try doing it a little faster, just for a few drops. see if the temperature increases dramatically, if not, maybe you can speed up your drips a bit. the only reason to do it slowly is to avoid heat/explosion yes? so then just adjust speed upwards until you are doing it faster but still well within safe parameters.
     
  7. flippy202

    flippy202 Member

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    to keep the reaction cool and under 10c one needs to drip at a rate of 1 drop every 7 seconds. (31% hcl) and this dude was using 35% hcl and did a whole liter in an hour and a half. hard to believe.
     
  8. andallthatstocome

    andallthatstocome not a squid

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    you could theoretically minimize the impact of a faster, hotter reaction by cooling it externally, like with an ice bath. lower starting temp=more energy required to be dangerous=faster reaction?
     
  9. DroneLore

    DroneLore h8rs gon h8, I stay based

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    Is DH2O heavy water?

    also flippy can you share the calculations you used to arrive at the rate of 1 drop / 7 seconds? Also I'm just curious as to what the exothermic reaction is. Is the the does the HCl protonate the NO2 and turn it into ammonia? Or does it have to do with the GABA (whose structure I don't know off the top of my head)?
     
  10. pharfromit

    pharfromit Member

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    no. dH2O is distilled water or deionized water (though most write DI for that).
     

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