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Posts 1 - 15 of 29   Subject: Another easy route to P-2-Pīs   Page:  All  Last  Next   Down

 
    Barium
(Newbee)
06-13-02 15:09
No 320730
      Another easy route to P-2-Pīs
(Rated as: excellent)
 Bookmark  Reply   

18,1g (100mmol) 1-(2-fluorophenyl)-2-nitropropene was added dry in portions to 49,5g (220mmol) SnCl2x2H2O suspended in 75ml EtOAc while the reaction temperature was kept between 20-40 deg C by a cold water bath. When all nitropropene was added and the color had changed to white (5 min) the EtOAc solution was transferred to a rb flask containing 250ml water and 50 ml hydrochloric acid. The EtOAc was removed by distillation under diminished pressure and the aqueous suspension of oxime and tin salts was allowed to stir at 80 deg C for 1 hour. The water phase was now steam distilled to remove the ketone. When no more oily drops came over the distillate was extracted with DCM. The DCM extracts was dried over MgSO4 and the DCM  removed by distillation leaving a quite pure ketone as a colorless oil.

Yield: 13,5g (89%) 1-(2-fluorophenyl)-2-propanone
Purity: 98% (HPLC)

Tin(II)chloride is quite non-toxic and generally very nice.   smile
 
 
 
 
    Rhodium
(Chief Bee)
06-13-02 15:30
No 320732
User Picture 
      Varma & Kabalka?  Bookmark  Reply   

Is this the procedure from Varma & Kabalka's paper, which I wrote about in TSII?

There have been reports of it not working so good in larger batches - but apparatly you've managed to do that. What are the physical properties of 2-Fluoro-P2P, and have you made the corresponding amphetamine or methamphetamine?
 
 
 
 
    Barium
(Newbee)
06-13-02 16:08
No 320736
      Itīs a variation of the Varma and Kabalka method, ...  Bookmark  Reply   

Itīs a variation of the Varma and Kabalka method, but they stopped at the oxime stage and said that it was just to extract the oxime with ether. Well the extraction of the oxime from the tin crap/sludge is a NIGHTMARE. So I thought way not render the whole thing acidic and hydrolyse the oxime to the ketone. At the same time the problem with the tin is no more, since Sn(II)chloride and Sn(IV)chloride will stay in the water phase.

I just did this two hours ago. First trial. Great success!!
The physical properties: bp 47 deg C @ 0,05mmHg, d 1,077g/ml according to Aldrich. Clear oily liquid with a aromatic smell, quite nice. I have not distilled it yet. I rarely do so with the ketones since I get them pure enough anyway. The amphetamine, N-methyl and N-ethyl will be made in a short while.
 
 
 
 
    Barium
(Newbee)
06-13-02 18:02
No 320761
      It just hit me  Bookmark  Reply   

This is another way of getting phenylacetones from nitropropenes without affecting aromatic halogens. So if someone starts with 2,5-dimethoxy-4-iodobenzaldehyde it seems easy enough to get the nitropropene-----phenylacetone----and get DOI without doing it the shulgin way.

Why does it seem like I am talking to myself the last days.
Not many replies to my posts. Donīt you guys and girls like them?frown
 
 
 
 
    Rhodium
(Chief Bee)
06-13-02 18:14
No 320769
User Picture 
      I love them! Haven't you noticed that I have ...  Bookmark  Reply   

I love them! Haven't you noticed that I have rated a large part of them as "excellent", and archived several of them at my site?

If you want some further discussion on the various topics you've brought up, then I'll try to do that - because encouraging you to post more of your ground-breaking stuff is definitely worth it.

How did the analysis go of the compound that wasn't 2C-H?
 
 
 
 
    Barium
(Newbee)
06-13-02 18:37
No 320780
      Ooops didnīt see that  Bookmark  Reply   

Sorry about that Rhodim! I havenīt visited your webpage for a couple of days now so I havenīt seen the updates youīve made until now. Iīm glad you liked them enough to archive them.

I have not had time to send the mysterious compound for a NMR yet. But it will be done.
According to the authors of the article I posted yesterday (nickel/hypophosphite), their method will reduce nitroparffins to amines. Letīs see if it reduces 1-(2,5-dimethoxyphenyl)-2-nitroethane to 2C-H as well....
It would also be nice to hear if someone else actually tries my methods.
 
 
 
 
    PrimoPyro
(Hive Prodigy)
06-13-02 18:37
No 320781
      rest assured I like reading your posts as well, I ...  Bookmark  Reply   

rest assured I like reading your posts as well, I just haven't been able to comment on any of them with anything significant. But just to let you know, I am also reading them and liking what I read. smile
 
 
 
 
    Barium
(Newbee)
06-13-02 18:39
No 320782
      Thanks PP!!.. :-)  Bookmark  Reply   

Thanks PP!!..smile
 
 
 
 
    Antoncho
(Official Hive Translator)
06-13-02 19:47
No 320801
      Questions  Bookmark  Reply   

Don't worry, Barium, it happens all the timesmile

Actually, i have two things to note:

1) In the known (Ritter's i think, no?) experiments the reduction was attempted on a nitrostyrene. As seen from those two articles posted by Yellium, they are more picky/less stable to the conditions. Maybee, that's the cause. Or maybee it's still the matter of ring-activation, or maybee both - i personally don't have a cluesmileblush

2) Barium, you used SnCl2 dihydrate - and in the original articles they said 'monohydrate'. I never heard of SnCl2*H2O - only the dihydrate, but maybee i'm just uninformed - what do you think?


Once again - your posts are a true pleasure to read, i'm glad you joyned uswink


Antoncho
 
 
 
 
    Barium
(Newbee)
06-14-02 17:34
No 321226
      This nitroalkene --> ketoxime --> ketone ...  Bookmark  Reply   

This nitroalkene --> ketoxime --> ketone was tried with two other phenyl-2-nitropropenes.

 
40,75g (250mmol) 1-phenyl-2-nitropropene
115g (512mmol, 2,05 eq.) SnCl2x2H2O
150ml EtOAc
140ml conc HCl
500mml water

yield; 30,82g (230mmol, 92%) 1-phenyl-2-propanone


51,75g (250mmol) 1-(3,4-methylenedioxyphenyl)-2-nitropropene
115g (512mmol, 2,05 eq.) SnCl2x2H2O
150ml EtOAC
140ml conc HCl
500ml water

yield; 41,83g (235mmol, 94%) 1-(3,4-methylenedioxyphenyl)-2-propanone
 
 
 
 
    Barium
(Newbee)
06-14-02 17:50
No 321230
      Hi Antoncho! Varma and Kabalka said that SnCl 2 ...  Bookmark  Reply   

Hi Antoncho!

Varma and Kabalka said that SnCl2/EtOAc doesnīt work with nitroethenes but does so with nitropropenes. I belive that the aldoxime doesnīt survive the enviroment but is hydrolysed to the acetaldehyde, which readily polymerises.

No I used SnCl2 not SnCl4. I have also only heard of either the anhydrous salt or the dihydrate of SnCl2.

Thank you for those kind words...smile
 
 
 
 
    Rhodium
(Chief Bee)
06-14-02 18:27
No 321251
User Picture 
      Varma & Kabalka made a followup to that paper, ...  Bookmark  Reply   

Varma & Kabalka made a followup to that paper, using basic SnCl2, and then it worked on both nitrostyrenes and nitropropenes.
 
 
 
 
    Antoncho
(Official Hive Translator)
06-14-02 20:29
No 321288
      Actually,....  Bookmark  Reply   

Rhodium, i'm not sure if we're talking of the same articles, but in Post 70459 (yellium: "Syn. Comm 18(7), 693-697 (1988)", Novel Discourse) the aldoximes were made under neutral conditions, while w/sodium stannite only Ph-nitropropenes were successfully reduced. It's not like i'm picking at youlaugh, just for the record.

So, anyway....... It's definitely a great news to hear that the same method works on, seemingly, ANY phenylnitropropene - SWIM would absolutely prefer this proc to electrolytic iron in GAA [yuck].

Saved it on my HD right away.



Antoncho
 
 
 
 
    Rhodium
(Chief Bee)
06-14-02 20:48
No 321293
User Picture 
      You are correct, I mixed the papers up in my head ...  Bookmark  Reply   

You are correct, I mixed the papers up in my head (Dave, my mind's going!). Reading the actual papers, I now saw that sodium stannite reduced phenylnitropropenes, while tin(II)chloride reduced both them and nitrostyrenes.

But I don't remember which method Ritter had problems with (getting polymers when scaling up over 2g).
 
 
 
 
    goiterjoe
(Title on BackOrder)
06-15-02 02:20
No 321410
User Picture 
      huh?  Bookmark  Reply   

In reply to:

Is this the procedure from Varma & Kabalka's paper, which I wrote about in TSII?



Did you write articles for Srike?  Or did you just slip up?
 
 

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