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All 15 posts Subject: Reduction of nitroalkenes with SnCl2 Please login to post Down

Antoncho
(Stranger)
11-10-00 09:56
No 68327
      Reduction of nitroalkenes with SnCl2

hi guys

Recently i was strolling across Rhodium's site and came upon a new post by Sonson that described convertion of MDP2P to its oxime followed by Na/EtOH reduction to MDA: https://www.rhodium.ws/chemistry/mdaoxime.html

The post itself was not THAT exciting but there was more:

"Different synthesis of oximes starting with nitroalkenes should be looked into, as this could be a good alternative to the existing methods for reducing nitroalkenes. SnCl2 reduces nitroalkenes to oximes under both acidic and basic conditions[14,15,16]... Another promising route is the use of Pb in DMF [18]. This seems to reduce most nitroalkenes to the corresponding oximes."

Now people these prosaic words have filled my chest with joy, bliss and a couple of words that my vocabulary just lacks. That's in view of the complete and absolute impossibility of getting LAH (and Uemura's prolonged and conspicious silence...)

The only fucking problem is that the place where i live is a God-forgotten, village populated exclusively by imbeciles and the closest chemistry library is like a thousand miles away - believe it or not :)

My point is: could anyone interested out there in the civilized part of the world look up the original articles and post them here, PLEASE!!! And you will have for ever my sincere friendship and, in case you happen to be a heterosexual female, incessant and most lascivious passion.

Also, SnCl2 is fairly easy to obtain - just bubble (dry) HCl into some melted tin (when cryst. from water it forms a really difficult to dehydrate hydrate). Anyone can speculate about an easier way? Maybe Sn(OH)2 in ethanolic HCl?

14. Tetr. Lett. 26;49;1985;6013-6014
15. Synth. Commun. 18;7;1988;693-698
16. Heterocycles 24;9;1986; 2581-2586
18. Tetrahedron 48;21;1992; 3313-26 among others

Antoncho
(Stranger)
11-11-00 07:50
No 68632
      Re: PLEASE, anyone...

oh i'm so sorry i just realized i didn't include the refs.
Here they are:

14. Tetr. Lett. 26;49;1985;6013-6014
15. Synth. Commun. 18;7;1988;693-698
16. Heterocycles 24;9;1986; 2581-2586
18. Tetrahedron 48;21;1992; 3313-26 among others

LaBTop
(Daddy)
11-12-00 14:29
No 68877
User Picture       Re: PLEASE, anyone...

Am very, very curious also.
Has anyone patent nrs covering this field? Then he and we can look them up in Esc@peNet. LT/

WISDOMwillWIN

PolytheneSam
(Hive Bee)
11-17-00 02:58
No 69740
      US Patents on this topic
(Rated as: excellent)

So, you're interested in patent numbers covering this stuff in general, ie. reduction of phenylnitropropenes, oximes, etc.? There's two very interesting subclasses at the US Patent Office, class 564 subclass 381 on phenethylamines with alpha alkyl substituents and subclass 382 on phenethylamines with beta alkyl substituents. There's plenty of stuff on phenylnitropropenes (as well as a lot of other reactions) including those with methoxy substituents

Here's what I found so far:

Patent US1879003 (inventor: Gorden Alles) on phenylisopropylamine via benzaldehyde and nitroethane -> phenylnitropropene which can be reduced by electrolytic reduction or by sodium amalgam in CH3COOH/EtOH, gives an example of electrolytic reduction but not the sodium amalgam reduction

Patent US2647930 catalytic reduction of nitroolefins (phenylnitropropene)

Patent US3198833 mentions in the prior art section P2P oxime reduction to the amine and P2Pol oxidation to P2P

Patent US2361372 m-CH3O-phenylnitropropene electrolytic reduction

Patent US3117160 reduction of nitroolefins (phenylnitropropenes)

Patent US3187046 discusses the apparent mechanism of catalytic hydrogenation of phenylnitropropenes to oximes which dissociate into ketones and ammonia which undergoes further reduction to the amine

Patent US1921424 discusses the conversion of dibenzyl ketone to the oxime and reduction of the oxime with Na and alcohol, no example process given. The amine is used as a decongestant.

This one is right on the money: Patent US2233823

PolytheneSam
(Hive Bee)
11-17-00 04:52
No 69759
      Re: PLEASE, anyone...

If anyone else wants to try Esc@peNet click the Rhodium link at the bottom of the page, click the chemistry link on Rhodium's page, scroll to the bottom and put in the US patent number to get a pdf of the patent.

I just tried looking at one of these patents at www.uspto.gov . Go to http://164.195.100.11/netahtml/srchnum.htm and put in the US patent number. If you don't have a TIFF plug-in or viewer I recommend AlternaTIFF. I've seen other people using it (with Netscape) and I just tried it with MSIE 5.5. You can get it here http://www.uspto.gov/web/menu/viewers.html

PolytheneSam
(Hive Bee)
11-21-00 11:34
No 70112
      Re: PLEASE, anyone...

This is right on the money. See US patent 2233823

PolytheneSam
(Hive Bee)
11-22-00 03:27
No 70233
      Re: PLEASE, anyone...

One thing I should mention is that the AlternaTIFF apparently didn't automatically put a .tif or .tiff extension on the filename when I downloaded patents from the USPTO site. You need to put one on when you create a filename to download it (third button from the left in AlternaTIFF) or you can put one on in Windows Explorer. You need the extension to view the patents in a browser offline. I did find that I can view the file in Kodak Imager and Previewer without the extension, but I don't know if everybody has them. Kodak Imager and Previewer was installed when I installed Win98SE. I never saw them in Win95, though.

I like using the tiff files better since they scroll faster in most viewers compared to .pdf files (from Espacenet) in Adobe Acrobat.

Sonson
(Stranger / Eraser)
11-22-00 10:33
No 70319
      Finally someones reacting...

I personally thinks the Pb/DMF route is the one. So if there is anyone with some Pb-powder...do some research! I've tried the SnCl2 in EtOAc and the results was someting deep black and not considered useful. And how about Zn in HAc?

Ritter
(Newbee)
11-22-00 21:19
No 70362
      Re: PLEASE, anyone...

I personally thinks the Pb/DMF route is the one
No way. Check this out:
Synth. Commun., 18, 693 (1988)
This reference uses easily obtainable SnCl2 in ethyl acetate to convert nitroolefins to oximes in near quantitative yields. The reference actually uses our favorite nitroalkene as an example. SWINM has run this rxn. on large scale w/ 2,5 Di MeO nitrostyrene and resulting dark red solid tar/chunky oxime reduced w/CTH (ammonium formate and Pd/C) for a fairly high yield of 2C-H.

Also see Post 192513 (Ritter: "Re: solubility of SnCl2 in H2O", Chemistry Discourse) /Rhodium

Sonson
(Stranger / Eraser)
11-23-00 08:19
No 70433
      Re: PLEASE, anyone...

I know the article yes...there are a buch of others too. Fairly good results was obtained with acetone when reducing 2,5-diMeO-6-nitro-B-nitrostyrene.
Why don't SWINM write the procedure up? Along with the appropriate analytical data of course...

yellium
(Hive Bee)
11-23-00 11:52
No 70459
      Syn. Comm 18(7), 693-697 (1988)
(Rated as: excellent)

Syn. Comm 18(7), 693-697 (1988)

Tin(II) halides have proven to be effective reducing agents in organics synthesis. Reactions involving stannous ions may be carried out under acidic, neutral or basic conditions and the product obtained are often pH dependent. in an earlier report, we noted that conjugated nitroalkenes were efficiently reduced to the corresponding ketoximes by tin(II) under basic conditions. Unfortunately, the method is not suitable for the preparations of aldoximes due to competing side reactions. A subsequent investigation revealed that ketoximes could also be generated by carrying out the reactions in neutral solvents. Once again, the reaction on conditions were not appropiate for preparation of aldoximes.

We now wish to report that nitroalkenes are readily reduced by SnCl2.2H2O to the corrsponding aldoximes in ethyl acetate at room temperature. Ketoximes are also obtained in excellent yields. The mildness of this method and the purity of the products obtained serve to extend the synthetic utility of stannous chloride, a safe and inexpensive reagent. The results are summarized in table I.

Experimental:
Commercially available samples (aldrich) of 1-nitro-1-cyclohexene, beta-nitrostyrene, and 9-(omega-nitrovinyl)anthracene were used as received. Other nitro compounds were prepared via published procedures. The products were characterized by their physical properties and spectral characterisitics (1H-NMR, 13c-NMR etc).

General procedure:
The synthesis of 9-anthracenylacetaldoxime is representative of the procedure employed. 9-(omega-nitrovinyl)anthracene (1.25 gr, 5 mmol), SnCl2.2H2O (2.25 gr, 10 mmol) and ethyl acetate (25 mL) were placed in a 50 mL erlenmeyer flask and the mixture stirred at room temperature. A mildly exothermic reaction ensued which was accompanied by the gradual disappearance of the yellow coloration (nitroalkene). The reaction mixture was carefully poured into ice water and the solution was made slightly basic (pH 7--8) by addition of 5% aqeous sodium bicarbonate. The product was extracted into ether, washed with brine, dried (Na2SO4) and the solvent removed under reduced presure to yield essentially pure 9-anthracenylacetaldoxime, mp 177-80' (1.05 gr, 90%).

table I:
product    time(h) yield (%)
R=n-hexyl,R1=H    4    91
R=phenyl,R1=H 6    94
R=p-isopropylphenyl,R1=H    6    92
R=1-napthyl,R1=H    8    93
R=9-anthracenyl,R1=H    8    90
R=p-bromophenyl,R1=Me 5    89
R,R1=cyclohexenyl 2    92

R-C=C-NO2 -> R-C-C=NOH
|    |
R1 R1

yellium
(Hive Bee)
11-23-00 12:10
No 70461
      Tet. Lett. 26(49), 6013-14 (1985)
(Rated as: excellent)

Tet. Lett. 26(49), 6013-14 (1985)

Tin(II) halides have been used extensively to reduce a variety of compounds under acidic conditions. However, only a few studies have been reported in which basic conditions were utilized (sodium stannite, Na2SnO2, forms under basic conditions). [...]
We wish to report that nitroalkenes are readily reduced by sodium stannite to the corresponding ketoximes at room temperature. These results contrast those obtained when the reactions were carried out under acidic or neutral conditions which resulted in the formation of alpha-substituted oxime derivatives.

The following procedure is representative: a sodium stannite solution was prepared by addition of aqeous sodium hydroxide (50 mmol, 2 gr in 15 ml of water) to aqeous stannous chloride (5 mmol, 1.12 gr in 15 ml water); the initially formed precipitate dissolved to form a clear solution. This solution was gradually added to the beta-nitrostyrene derivative (2 mmol, in 10 ml THF) at room temperature; a mildly exothermic reaction ensued. The reaction mixture was stirred for the specified time, saturated brine solution added, the product extracted into ether, (3x45 ml) and the worked up in the susual manner. Essentially pure product were obtained.

nitroalkene

   R R
CH=C-NO2 CH2-C=NOH
|    |
.
/ \    /.\
|O| ->   |O|
\./-R2 \./-R2
|    |
R1 R1

R R1 R2 time (min) Yield (as isolated, %)
CH3 H    H    25    82
CH3 Br H    40    84
CH3 OEt   OEt    90    71

psyloxy
(Hive Addict)
11-23-00 19:38
No 70536
User Picture       Re: PLEASE, anyone...

How is Urushibara Ni at reducing oximes ? Maybe it's better at this then at reducing nitrostyrenes ?

--psyloxy--

Rhodium
(Chief Bee)
03-12-04 13:36
No 494625
      Nitroalkene reduction with Tin(II) - full articles
(Rated as: excellent)

_{Part of these articles posted before in the following posts:
Post 70459 (yellium: "Syn. Comm 18(7), 693-697 (1988)", Novel Discourse)
Post 70461 (yellium: "Tet. Lett. 26(49), 6013-14 (1985)", Novel Discourse)}

A Facile Ketoxime Preparation via the Reduction of ,-Unsaturated Nitroalkenes Using Sodium Stannite
Rajender S. Varma, Manju Varma and George W. Kabalka
Tetrahedron Letters 26(49), 6013-6014 (1985) (https://www.rhodium.ws/pdf/nitroalkene-stannite-1.pdf)

Abstract
,-Unsaturated nitroalkenes are readily reduced by sodium stannite to ketoximes at room temperature.
____ ___ __ _

A Facile Aldoxime Preparation via the Reduction of ,-Unsaturated Nitroalkenes Using Tin(II)Chloride
George W. Kabalka and Naganna M. Goudgaon
Synthetic Communications 18(7), 693-697 (1988) (https://www.rhodium.ws/pdf/nitroalkene-stannite-2.pdf)

Abstract
,-Unsaturated nitroalkenes are readily reduced by SnCl₂·2H₂O in ethyl acetate to the aldoximes in high yield at room temperature.

^{The Hive - Clandestine Chemists Without Borders}

Rhodium
(Chief Bee)
03-13-04 01:42
No 494753
User Picture       More Nitroalkene to Oxime Reduction References
(Rated as: excellent)

Reduction of Nitroalkenes With Stannous Chloride in Non-Acidic and Non-Aqueous Medium. Synthesis of -Substituted Oximes
R. S. Varma and G. W. Kabalka
Chem. Lett. 243-244 (1985) (https://www.rhodium.ws/pdf/nitroalkene.sncl2-roh.pdf)

Abstract
,-Unsaturated nitroalkenes are readily reduced by SnCl₂·2H₂O in alcoholic media to the -alkoxy oxime derivatives in high yields. In the presence of ethanethiol, the corresponding -alkylthio oximes are formed.
^{This Article has been mentioned before in the following post:
Post 468014 (imp: "How about these possibilities?", Methods Discourse)}
____ ___ __ _

Stannous Chloride Reduction of ,-Unsaturated Nitroalkenes: A Direct Synthesis of 2-Aryl-2H-1-Benzopyran-3(4H)-One Oximes
R. S. Varma, M. Varma, Y.-Z. Gai and G. W. Kabalka
Heterocycles 24(9), 2581-2586 (1985) (https://www.rhodium.ws/pdf/nitroalkene.sncl2-chromane.pdf)

Abstract
Stannous chloride, in acetone, readily reduced the ,-unsaturated nitroalkenes to the corresponding oximes at room temperature. A series of 2-aryl-3-chromanone oximes were obtained via the reduction of 3-nitrochromenes.
^{This Article has been mentioned before in the following post:
Post 68327 (Antoncho: "Reduction of nitroalkenes with SnCl2", Novel Discourse)
Post 190061 (Antibody2: "nitropropene >> oxime", Chemistry Discourse)}
____ ___ __ _

A Facile Synthesis of Oximes from 1-Nitro-1-alkenes by Lead Reduction
Akira Sera, Hidemi Yamauchi, Hiroaki Yamada, Kuniaki Itoh
Synlett 477-478 (1990) (https://www.rhodium.ws/chemistry/nitroalkene2oxime.pb-dmf.html)

Abstract
The reduction of 1-nitro-1-alkenes with lead–acetic acid in dimethylformamide afforded the corresponding aldoximes (5 examples) or ketoximes (3 examples) in excellent yield.

^{This Article has been mentioned before in the following post:
Post 242123 (Cyrax: "Re: Synthesis of amphetamines", Methods Discourse)
Post 254783 (Cyrax: "Re: Russian patents works!!! Zn-HCl nitrostryrene", Novel Discourse)}

^{The Hive - Clandestine Chemists Without Borders}

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	All 15 posts		Subject: Reduction of nitroalkenes with SnCl2		Please login to post		Down


		Antoncho (Stranger) 11-10-00 09:56 No 68327				Reduction of nitroalkenes with SnCl2
						hi guys Recently i was strolling across Rhodium's site and came upon a new post by Sonson that described convertion of MDP2P to its oxime followed by Na/EtOH reduction to MDA: https://www.rhodium.ws/chemistry/mdaoxime.html The post itself was not THAT exciting but there was more: "Different synthesis of oximes starting with nitroalkenes should be looked into, as this could be a good alternative to the existing methods for reducing nitroalkenes. SnCl2 reduces nitroalkenes to oximes under both acidic and basic conditions[14,15,16]... Another promising route is the use of Pb in DMF [18]. This seems to reduce most nitroalkenes to the corresponding oximes." Now people these prosaic words have filled my chest with joy, bliss and a couple of words that my vocabulary just lacks. That's in view of the complete and absolute impossibility of getting LAH (and Uemura's prolonged and conspicious silence...) The only fucking problem is that the place where i live is a God-forgotten, village populated exclusively by imbeciles and the closest chemistry library is like a thousand miles away - believe it or not :) My point is: could anyone interested out there in the civilized part of the world look up the original articles and post them here, PLEASE!!! And you will have for ever my sincere friendship and, in case you happen to be a heterosexual female, incessant and most lascivious passion. Also, SnCl2 is fairly easy to obtain - just bubble (dry) HCl into some melted tin (when cryst. from water it forms a really difficult to dehydrate hydrate). Anyone can speculate about an easier way? Maybe Sn(OH)2 in ethanolic HCl? 14. Tetr. Lett. 26;49;1985;6013-6014 15. Synth. Commun. 18;7;1988;693-698 16. Heterocycles 24;9;1986; 2581-2586 18. Tetrahedron 48;21;1992; 3313-26 among others



		Antoncho (Stranger) 11-11-00 07:50 No 68632				Re: PLEASE, anyone...
						oh i'm so sorry i just realized i didn't include the refs. Here they are: 14. Tetr. Lett. 26;49;1985;6013-6014 15. Synth. Commun. 18;7;1988;693-698 16. Heterocycles 24;9;1986; 2581-2586 18. Tetrahedron 48;21;1992; 3313-26 among others



		LaBTop (Daddy) 11-12-00 14:29 No 68877				Re: PLEASE, anyone...
						Am very, very curious also. Has anyone patent nrs covering this field? Then he and we can look them up in Esc@peNet. LT/ WISDOMwillWIN



		PolytheneSam (Hive Bee) 11-17-00 02:58 No 69740				US Patents on this topic (Rated as: excellent)
						So, you're interested in patent numbers covering this stuff in general, ie. reduction of phenylnitropropenes, oximes, etc.? There's two very interesting subclasses at the US Patent Office, class 564 subclass 381 on phenethylamines with alpha alkyl substituents and subclass 382 on phenethylamines with beta alkyl substituents. There's plenty of stuff on phenylnitropropenes (as well as a lot of other reactions) including those with methoxy substituents Here's what I found so far: Patent US1879003 (inventor: Gorden Alles) on phenylisopropylamine via benzaldehyde and nitroethane -> phenylnitropropene which can be reduced by electrolytic reduction or by sodium amalgam in CH3COOH/EtOH, gives an example of electrolytic reduction but not the sodium amalgam reduction Patent US2647930 catalytic reduction of nitroolefins (phenylnitropropene) Patent US3198833 mentions in the prior art section P2P oxime reduction to the amine and P2Pol oxidation to P2P Patent US2361372 m-CH3O-phenylnitropropene electrolytic reduction Patent US3117160 reduction of nitroolefins (phenylnitropropenes) Patent US3187046 discusses the apparent mechanism of catalytic hydrogenation of phenylnitropropenes to oximes which dissociate into ketones and ammonia which undergoes further reduction to the amine Patent US1921424 discusses the conversion of dibenzyl ketone to the oxime and reduction of the oxime with Na and alcohol, no example process given. The amine is used as a decongestant. This one is right on the money: Patent US2233823



		PolytheneSam (Hive Bee) 11-17-00 04:52 No 69759				Re: PLEASE, anyone...
						If anyone else wants to try Esc@peNet click the Rhodium link at the bottom of the page, click the chemistry link on Rhodium's page, scroll to the bottom and put in the US patent number to get a pdf of the patent. I just tried looking at one of these patents at www.uspto.gov . Go to http://164.195.100.11/netahtml/srchnum.htm and put in the US patent number. If you don't have a TIFF plug-in or viewer I recommend AlternaTIFF. I've seen other people using it (with Netscape) and I just tried it with MSIE 5.5. You can get it here http://www.uspto.gov/web/menu/viewers.html



		PolytheneSam (Hive Bee) 11-21-00 11:34 No 70112				Re: PLEASE, anyone...
						This is right on the money. See US patent 2233823



		PolytheneSam (Hive Bee) 11-22-00 03:27 No 70233				Re: PLEASE, anyone...
						One thing I should mention is that the AlternaTIFF apparently didn't automatically put a .tif or .tiff extension on the filename when I downloaded patents from the USPTO site. You need to put one on when you create a filename to download it (third button from the left in AlternaTIFF) or you can put one on in Windows Explorer. You need the extension to view the patents in a browser offline. I did find that I can view the file in Kodak Imager and Previewer without the extension, but I don't know if everybody has them. Kodak Imager and Previewer was installed when I installed Win98SE. I never saw them in Win95, though. I like using the tiff files better since they scroll faster in most viewers compared to .pdf files (from Espacenet) in Adobe Acrobat.



		Sonson (Stranger / Eraser) 11-22-00 10:33 No 70319				Finally someones reacting...
						I personally thinks the Pb/DMF route is the one. So if there is anyone with some Pb-powder...do some research! I've tried the SnCl2 in EtOAc and the results was someting deep black and not considered useful. And how about Zn in HAc?



		Ritter (Newbee) 11-22-00 21:19 No 70362				Re: PLEASE, anyone...
						I personally thinks the Pb/DMF route is the one No way. Check this out: Synth. Commun., 18, 693 (1988) This reference uses easily obtainable SnCl2 in ethyl acetate to convert nitroolefins to oximes in near quantitative yields. The reference actually uses our favorite nitroalkene as an example. SWINM has run this rxn. on large scale w/ 2,5 Di MeO nitrostyrene and resulting dark red solid tar/chunky oxime reduced w/CTH (ammonium formate and Pd/C) for a fairly high yield of 2C-H. Also see Post 192513 (Ritter: "Re: solubility of SnCl2 in H2O", Chemistry Discourse) /Rhodium



		Sonson (Stranger / Eraser) 11-23-00 08:19 No 70433				Re: PLEASE, anyone...
						I know the article yes...there are a buch of others too. Fairly good results was obtained with acetone when reducing 2,5-diMeO-6-nitro-B-nitrostyrene. Why don't SWINM write the procedure up? Along with the appropriate analytical data of course...



		yellium (Hive Bee) 11-23-00 11:52 No 70459				Syn. Comm 18(7), 693-697 (1988) (Rated as: excellent)
						Syn. Comm 18(7), 693-697 (1988) Tin(II) halides have proven to be effective reducing agents in organics synthesis. Reactions involving stannous ions may be carried out under acidic, neutral or basic conditions and the product obtained are often pH dependent. in an earlier report, we noted that conjugated nitroalkenes were efficiently reduced to the corresponding ketoximes by tin(II) under basic conditions. Unfortunately, the method is not suitable for the preparations of aldoximes due to competing side reactions. A subsequent investigation revealed that ketoximes could also be generated by carrying out the reactions in neutral solvents. Once again, the reaction on conditions were not appropiate for preparation of aldoximes. We now wish to report that nitroalkenes are readily reduced by SnCl2.2H2O to the corrsponding aldoximes in ethyl acetate at room temperature. Ketoximes are also obtained in excellent yields. The mildness of this method and the purity of the products obtained serve to extend the synthetic utility of stannous chloride, a safe and inexpensive reagent. The results are summarized in table I. Experimental: Commercially available samples (aldrich) of 1-nitro-1-cyclohexene, beta-nitrostyrene, and 9-(omega-nitrovinyl)anthracene were used as received. Other nitro compounds were prepared via published procedures. The products were characterized by their physical properties and spectral characterisitics (1H-NMR, 13c-NMR etc). General procedure: The synthesis of 9-anthracenylacetaldoxime is representative of the procedure employed. 9-(omega-nitrovinyl)anthracene (1.25 gr, 5 mmol), SnCl2.2H2O (2.25 gr, 10 mmol) and ethyl acetate (25 mL) were placed in a 50 mL erlenmeyer flask and the mixture stirred at room temperature. A mildly exothermic reaction ensued which was accompanied by the gradual disappearance of the yellow coloration (nitroalkene). The reaction mixture was carefully poured into ice water and the solution was made slightly basic (pH 7--8) by addition of 5% aqeous sodium bicarbonate. The product was extracted into ether, washed with brine, dried (Na2SO4) and the solvent removed under reduced presure to yield essentially pure 9-anthracenylacetaldoxime, mp 177-80' (1.05 gr, 90%). table I: product time(h) yield (%) R=n-hexyl,R1=H 4 91 R=phenyl,R1=H 6 94 R=p-isopropylphenyl,R1=H 6 92 R=1-napthyl,R1=H 8 93 R=9-anthracenyl,R1=H 8 90 R=p-bromophenyl,R1=Me 5 89 R,R1=cyclohexenyl 2 92 R-C=C-NO2 -> R-C-C=NOH \| \| R1 R1



		yellium (Hive Bee) 11-23-00 12:10 No 70461				Tet. Lett. 26(49), 6013-14 (1985) (Rated as: excellent)
						Tet. Lett. 26(49), 6013-14 (1985) Tin(II) halides have been used extensively to reduce a variety of compounds under acidic conditions. However, only a few studies have been reported in which basic conditions were utilized (sodium stannite, Na2SnO2, forms under basic conditions). [...] We wish to report that nitroalkenes are readily reduced by sodium stannite to the corresponding ketoximes at room temperature. These results contrast those obtained when the reactions were carried out under acidic or neutral conditions which resulted in the formation of alpha-substituted oxime derivatives. The following procedure is representative: a sodium stannite solution was prepared by addition of aqeous sodium hydroxide (50 mmol, 2 gr in 15 ml of water) to aqeous stannous chloride (5 mmol, 1.12 gr in 15 ml water); the initially formed precipitate dissolved to form a clear solution. This solution was gradually added to the beta-nitrostyrene derivative (2 mmol, in 10 ml THF) at room temperature; a mildly exothermic reaction ensued. The reaction mixture was stirred for the specified time, saturated brine solution added, the product extracted into ether, (3x45 ml) and the worked up in the susual manner. Essentially pure product were obtained. nitroalkene R R CH=C-NO2 CH2-C=NOH \| \| . / \ /.\ \|O\| -> \|O\| \./-R2 \./-R2 \| \| R1 R1 R R1 R2 time (min) Yield (as isolated, %) CH3 H H 25 82 CH3 Br H 40 84 CH3 OEt OEt 90 71



		psyloxy (Hive Addict) 11-23-00 19:38 No 70536				Re: PLEASE, anyone...
						How is Urushibara Ni at reducing oximes ? Maybe it's better at this then at reducing nitrostyrenes ? --psyloxy--



		Rhodium (Chief Bee) 03-12-04 13:36 No 494625				Nitroalkene reduction with Tin(II) - full articles (Rated as: excellent)
						_{Part of these articles posted before in the following posts: Post 70459 (yellium: "Syn. Comm 18(7), 693-697 (1988)", Novel Discourse) Post 70461 (yellium: "Tet. Lett. 26(49), 6013-14 (1985)", Novel Discourse)} A Facile Ketoxime Preparation via the Reduction of ,-Unsaturated Nitroalkenes Using Sodium Stannite Rajender S. Varma, Manju Varma and George W. Kabalka Tetrahedron Letters 26(49), 6013-6014 (1985) (https://www.rhodium.ws/pdf/nitroalkene-stannite-1.pdf) Abstract ,-Unsaturated nitroalkenes are readily reduced by sodium stannite to ketoximes at room temperature. ____ ___ __ _ A Facile Aldoxime Preparation via the Reduction of ,-Unsaturated Nitroalkenes Using Tin(II)Chloride George W. Kabalka and Naganna M. Goudgaon Synthetic Communications 18(7), 693-697 (1988) (https://www.rhodium.ws/pdf/nitroalkene-stannite-2.pdf) Abstract ,-Unsaturated nitroalkenes are readily reduced by SnCl₂·2H₂O in ethyl acetate to the aldoximes in high yield at room temperature. ^{The Hive - Clandestine Chemists Without Borders}



		Rhodium (Chief Bee) 03-13-04 01:42 No 494753				More Nitroalkene to Oxime Reduction References (Rated as: excellent)
						Reduction of Nitroalkenes With Stannous Chloride in Non-Acidic and Non-Aqueous Medium. Synthesis of -Substituted Oximes R. S. Varma and G. W. Kabalka Chem. Lett. 243-244 (1985) (https://www.rhodium.ws/pdf/nitroalkene.sncl2-roh.pdf) Abstract ,-Unsaturated nitroalkenes are readily reduced by SnCl₂·2H₂O in alcoholic media to the -alkoxy oxime derivatives in high yields. In the presence of ethanethiol, the corresponding -alkylthio oximes are formed. ^{This Article has been mentioned before in the following post: Post 468014 (imp: "How about these possibilities?", Methods Discourse)} ____ ___ __ _ Stannous Chloride Reduction of ,-Unsaturated Nitroalkenes: A Direct Synthesis of 2-Aryl-2H-1-Benzopyran-3(4H)-One Oximes R. S. Varma, M. Varma, Y.-Z. Gai and G. W. Kabalka Heterocycles 24(9), 2581-2586 (1985) (https://www.rhodium.ws/pdf/nitroalkene.sncl2-chromane.pdf) Abstract Stannous chloride, in acetone, readily reduced the ,-unsaturated nitroalkenes to the corresponding oximes at room temperature. A series of 2-aryl-3-chromanone oximes were obtained via the reduction of 3-nitrochromenes. ^{This Article has been mentioned before in the following post: Post 68327 (Antoncho: "Reduction of nitroalkenes with SnCl2", Novel Discourse) Post 190061 (Antibody2: "nitropropene >> oxime", Chemistry Discourse)} ____ ___ __ _ A Facile Synthesis of Oximes from 1-Nitro-1-alkenes by Lead Reduction Akira Sera, Hidemi Yamauchi, Hiroaki Yamada, Kuniaki Itoh Synlett 477-478 (1990) (https://www.rhodium.ws/chemistry/nitroalkene2oxime.pb-dmf.html) Abstract The reduction of 1-nitro-1-alkenes with lead–acetic acid in dimethylformamide afforded the corresponding aldoximes (5 examples) or ketoximes (3 examples) in excellent yield. ^{This Article has been mentioned before in the following post: Post 242123 (Cyrax: "Re: Synthesis of amphetamines", Methods Discourse) Post 254783 (Cyrax: "Re: Russian patents works!!! Zn-HCl nitrostryrene", Novel Discourse)} ^{The Hive - Clandestine Chemists Without Borders}

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