hest
(Hive Adickt)
11-07-02 16:54
No 377467
      nitropropen (DOM) made with microwawes
(Rated as: excellent)
 Bookmark   

Don't know if this is old news, any way
9g 4-methy-2,5-dimethoxybenzaldehyde, 4,5g Nitroethane and 1g cyclohexylamin was heated in a domestic microwawe owen set on defrost (125W) two times 5min seperated with 10min 'cool down' period. Then another 4,5g nitroethan and 1g cyclohexylamin was introduced and the heating cycle repeted.
To the red, still hot, solution was then added 25mL ethanol. The solution was cooled in a icebad, and white edit yellow glinsering xtals was filtered off.
Yeald 8,2g

TLC:(40%DCM in Pet.ether)
Rf for the nitropropene 0,59   Rf for the aldehyde 0,46
 
 
 
 
    Rhodium
(Chief Bee)
11-07-02 17:55
No 377492
      Microwave Nitrostyrenes  Bookmark   

Nice! I really like when people dare to try new techniques and post about them!

Starting materials:
50 mmol 4-Methyl-2,5-dimethoxybenzaldehyde
20 mmol cyclohexylamine (2x10 mmol)
120 mmol nitroethane (2x60 mmol)

Product:
34.6 mmol 4-Methyl-2,5-dimethoxyphenyl-2-nitropropene (70% yield)

Did you use ../rhodium/pdf /mw.nitroalkene.pdf as a starting point?

The "white glistening crystals" you filtered off - was that unreacted benzaldehyde? 4-Methyl-2,5-dimethoxyphenyl-2-nitropropene is supposed to be orange!
 
 
 
 
    hest
(Hive Adickt)
11-07-02 19:58
No 377546
      Microwawes  Bookmark   

No I ment the yellow xtals, usual it's white xtal I filter off (laugh) old habit.
The story is actual that I made the aldehyde from toluhydroquinon (inspired from the article wit n-methyl-foramid(shuligin has a copy of it in his 2c-d synth) it work's like a charm). Then I did the usual boilin af the aldehyde with amm.acetate in acetic for 3 houers, ending op with 9g of starting material !! crazy
Then I had to try something new, and I have made 2C-H with microwawes some years ago, can't remember where I heard the idear, but I guess it was at the hive. So i gave it a try (the firs 100mg burned (as usual) but I could detect the product all over the owen (laugh).
guess that's id. I think I will boil it in ether with some LAH now. 
 
 
 
 
    Rhodium
(Chief Bee)
11-07-02 20:41
No 377553
      Have you seen the document at http://www.rhodium.  Bookmark   

Have you seen the document at ../rhodium/chemistry /stp.html - with my hugely improved synthesis of the benzaldehyde, where the yield is more than tripled, and with less work, too.

How do you make 2C-H in the microwave? Do you still have your lab notes for that?
 
 
 
 
    hest
(Hive Adickt)
11-07-02 20:54
No 377556
      Condensation  Bookmark   

Yes, I have seen the aldehyde synth. I methylate with KOH in wather and then boil. yeald close to 100%. The Wilsmeyer with NMFA is so much more effective than with DMF. after 50min I get a yellow chunk of the comples, add the toluene and heat to 70C for 2 houers. yeald in the 80's.
No don't have lab notes to the 2c-h synth (usual I don't keep not on that kind of chemistrywink). But I take one mole aldehyde, mixing it with 1 mole nitro (m)ethane and some am.formiat (sure all the other amines work), nuke 2 times with enough power to let it boil good but not eksplode, then I add one more mole nitro and a dash amine, nuke again and clean up. you are home within 30min.
When the reaction i running you can see small droplets of wather forming and then boiling off. I'm sure that is one of the reasons why it works so greath. Maby it would bee worth a try to put a watherpump onto the system ? (My owen has mounted a metal pipe on the roof, greath for refluxinglaugh)
 
 
 
 
    Rhodium
(Chief Bee)
11-07-02 21:16
No 377563
      Aha  Bookmark   

Okay, so it was the same kind of reaction, benzaldehyde/nitroalkane condensation. When you said 2C-H, I thought you had devised something allowing you to microwave your way through the reduction part too.
 
 
 
 
    hest
(Hive Adickt)
11-07-02 21:44
No 377577
      Nope  Bookmark   

Nope haven't done that yet. Still working with LAH. I can't get consisten result with the kombination of hydrogen under presure and Pd/C then RaNi. The NaBH4 and Al/Hg sound's to sloggy to mee too. Hope the aziridinething turn's out to work some day (I have made the 1-amino-isopropanol from propyloxiran, but ther is still loong way to the goal)

keep cooking
Hest
 
 
 
 
    ClearLight
(Hive Addict)
11-08-02 13:11
No 377764
      THX  Bookmark   


  For the tlc solvents and rF's...


Infinite Radiant Light - THKRA
 
 
 
 
    SPISSHAK
(Hive Bee)
11-08-02 18:27
No 377858
      Hest  Bookmark   

Did you run a tlc on your produkt? (no pun intended)
If so give us some results.