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Synthesis of Benzoquinone
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| Author | Topic: Total Synthesis of Benzoquinone |
| spiceboy Member |
posted 10-05-98 09:05 AM
Hello Bees....Today I am going to step out of character and give something that I am not known for giving...DETAILS..... We all know that benzoquinone is a desirable substance. It is the keystone of a supersimple, highly efficient synthetic route to the beloved MDP2P.... Commercially, it is prepared by the oxidation of aniline w/ MnO2 in acid... But not this way.....
23g hydroquinone
Upon removal of the flask from the ice bath, add the dichromate in portions,(5) with swirling, S-L-O-W-L-Y. It'll take about 5-10 minutes.You may need to monitor the Rx temp to keep it at 25 degrees or so... In the early stage of oxidation, a precipitate separates that is a
green-blackish color, this is the so-called quinhydrone complex, and is a
good sign...in the later stages, as the reaction completes, the color of
the precip changes to yellow-green, almost day-glo-ish.... Cool mixture to 5 degrees. Filter crystals on a buchner.They are benzoquinone.Wash the crude crystals with a SMALL portion of ice-cold dH2O. This is good enough to use as is, but sublimation is a straitforward alternative for you purity freaks. Bright yellow crystals declorize upon standing, so its probably a good idea to make this on an as-needed basis. Yields: about 14g or 60+%.... BOOM. ZOWIE.
Go forth and bee fruitful. |
| spiceboy Member |
posted 10-05-98 10:13 AM
I abandoned the napthalene idea 'cause it just stinks too fucking bad.... |
| spiceboy Member |
posted 10-05-98 10:13 AM
I abandoned the napthalene idea 'cause it just stinks too fucking bad.... |
| boingo Member |
posted 10-05-98 10:47 AM
but you didn't tell us how to make p-benzo out of dirt and lawn clippings. you suck! awesome! |
| boingo Member |
posted 10-05-98 10:47 AM
but you didn't tell us how to make p-benzo out of dirt and lawn clippings. you suck! awesome! |
| spiceboy Member |
posted 10-05-98 11:19 AM
I have a synthesis using dirt and lawn clippings, but it takes about 9 months for a decent yield..... ;-) you may need a little miracle-gro |
| spiceboy Member |
posted 10-05-98 11:19 AM
I have a synthesis using dirt and lawn clippings, but it takes about 9 months for a decent yield..... ;-) you may need a little miracle-gro |
| spiceboy Member |
posted 10-05-98 01:23 PM
.....and the yield is pretty good, too!(cough cough...) |
| spiceboy Member |
posted 10-05-98 01:23 PM
.....and the yield is pretty good, too!(cough cough...) |
| spiceboy Member |
posted 10-06-98 09:11 AM
Oh, yeah....Benzoquinone is amazingly irritating to the respiratory tract, and eyes. It seems to be *quite* volatile. |
| spiceboy Member |
posted 10-06-98 09:11 AM
Oh, yeah....Benzoquinone is amazingly irritating to the respiratory tract, and eyes. It seems to be *quite* volatile. |
| quirks Member |
posted 10-06-98 09:27 AM
I hear there's some pyrotech shops with potassium dichromate for 70$/10lbs... |
| quirks Member |
posted 10-06-98 09:27 AM
I hear there's some pyrotech shops with potassium dichromate for 70$/10lbs... |
| Cozmic
Charley unregistered |
posted 10-06-98 09:41 AM
Wow! Maybe I won't have to buy that benzoquinone! Good work SB! |
| Cozmic
Charley unregistered |
posted 10-06-98 09:41 AM
Wow! Maybe I won't have to buy that benzoquinone! Good work SB! |
| ketone Member |
posted 10-06-98 09:44 AM
That's a ridiculous price for potassium dichromate! My friendly photographic supplier lists the potassium flavor @ $13.70/lb and the sodium flavor for $10.00/lb. -ketone |
| ketone Member |
posted 10-06-98 09:44 AM
That's a ridiculous price for potassium dichromate! My friendly photographic supplier lists the potassium flavor @ $13.70/lb and the sodium flavor for $10.00/lb. -ketone |
| ChemHack Member |
posted 10-06-98 12:34 PM
Hey Ketone, that works out to only $7/lb. |
| ChemHack Member |
posted 10-06-98 12:34 PM
Hey Ketone, that works out to only $7/lb. |
| Joe
uGly Member |
posted 10-06-98 01:50 PM
500G's for 14 bucks at the Alliance. or 2.5K for 55 bucks http://www.txdirect.net/users/scially/pricesp.htm Joe |
| Joe
uGly Member |
posted 10-06-98 01:50 PM
500G's for 14 bucks at the Alliance. or 2.5K for 55 bucks http://www.txdirect.net/users/scially/pricesp.htm Joe |
| quirks Member |
posted 10-06-98 02:40 PM
Fi$her has it for only 100$/500g!! |
| quirks Member |
posted 10-06-98 02:40 PM
Fi$her has it for only 100$/500g!! |
| Rhodium Administrator |
posted 10-06-98 05:14 PM
I have a few more benzoquinone synths at http://www.lycaeum.org/~rhodium/chemistry/quinones.txt |
| Rhodium Administrator |
posted 10-06-98 05:14 PM
I have a few more benzoquinone synths at http://www.lycaeum.org/~rhodium/chemistry/quinones.txt |
| spiceboy Member |
posted 10-26-98 11:25 AM
I think these are going to be good synths to archive, 'cause the benzoquinone route is turning out to be a nice one............ |
| spiceboy Member |
posted 10-26-98 11:25 AM
I think these are going to be good synths to archive, 'cause the benzoquinone route is turning out to be a nice one............ |
| Ritter Member |
posted 10-27-98 10:52 PM
Question on the color of Benzoquinone: Someone followed the instructions for this material presented in Org Syn Coll Vol I (oxidation of hydroquinone w/ sulfuric/chromate), forgot about the mess and came back about two weeks later to collect his product of precious benzoquinone. Only problem was that the isolated crystals were a dark green color. Does anyone know if it is normal for benzoquinones yellow color to degrade to dark olive green, and if so is the material useless at this point? Can it possibly be recrystallized to yellow crystals? Any help appreciated. Tks, |
| Ritter Member |
posted 10-27-98 10:52 PM
Question on the color of Benzoquinone: Someone followed the instructions for this material presented in Org Syn Coll Vol I (oxidation of hydroquinone w/ sulfuric/chromate), forgot about the mess and came back about two weeks later to collect his product of precious benzoquinone. Only problem was that the isolated crystals were a dark green color. Does anyone know if it is normal for benzoquinones yellow color to degrade to dark olive green, and if so is the material useless at this point? Can it possibly be recrystallized to yellow crystals? Any help appreciated. Tks, |
| ketone Member |
posted 10-27-98 11:26 PM
Doh! Quinone should be stored in a sealed container...it sublimes and oxydizes if I remember correctly. Think you'd better start again 
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| ketone Member |
posted 10-27-98 11:26 PM
Doh! Quinone should be stored in a sealed container...it sublimes and oxydizes if I remember correctly. Think you'd better start again
|
| ChemHack Member |
posted 10-27-98 11:42 PM
Ain't basic chrome green? |
| ChemHack Member |
posted 10-27-98 11:42 PM
Ain't basic chrome green? |
| spiceboy Member |
posted 10-28-98 09:27 AM
I believe you would be better served to begin over. However, you may actually still have some product in there. How to get it out, I dont know.... |
| spiceboy Member |
posted 10-28-98 09:27 AM
I believe you would be better served to begin over. However, you may actually still have some product in there. How to get it out, I dont know.... |
| ChemHack Member |
posted 11-14-98 04:47 AM
43g crushed mothballs 49g KCrO4 36g H2O4 Cromate dissolved (mostly) in 100ml tap water. Seems slightly endothermic. Yellow. Acid dissolved in 150 ice-water. Exothermic. Added acid to chromate solution. Percipitate fell out. Dark orange color. Dichromate formation? Added chromate/acid to powdered mothballs. 100x50x50 washes tap water washes of chromate/acid container added as well. No noticeable change in temp. No noticeable change in anything. Larger chunks of mothballs undissolved. Hmmmmmm..... Now what? |
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