Acetaldehyde + CH3MgBr -> Pol. -Piglet

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dormouse
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04-20-00 02:04
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acetaldehyde + CH3MgBr -> Pol. -Piglet
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acetaldehyde + CH3MgBr -> Pol.

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Author Topic:   acetaldehyde + CH3MgBr -> Pol.
Piglet
Member   posted 06-10-98 09:50 AM
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I have read that phenyl acetaldehyde can be converted to 1-phenyl 2-propanol with methyl magnesium bromide. Since I worked out an OTC route to the aldehyde, I would like to try this out. Has anyone ever come across this before ?
Combined with --7 this might bee a nice route. Also, l-dopa (from broadbeans) could be converted to 3,4 dihydroxy phenyl acetaldehyde and so on and so forth.
I seem to remember someone suggesting this before, but I took no notice (stoopid me). So if it was you, sorry, tell me again!

Best wishes to you all,
Piglet

Labrat
Member   posted 06-10-98 10:41 AM
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Phenylacetaldehyde can be used for an easy method to make ----:
1)make the imine between methylamine and phenylacetaldehyde by refluxing equimolar amounts of the chems in toluene, collecting the water in a Dean-Stark trap. Distill of the toluene and distill the imine.

2)prepare methylmagnesium Grignard in ether by adding methyliodide to a magnesium/ether solution.

3)Add the imine, dissolved in a little ether, dropwise to the methylmagnesium Grignard (1.5 equivalents). After the addition, bring the mixture to reflux. Decompose the Grignard with NH4Cl... after standard workup you should have a good yield of ----.

I can remember someone else posting this variant, so if that someone could please come and get the credit for it! I only post this because I happened to be reading refs about this method and think this is a better purpose for your phenacetaldehyde. Lr/

Labrat
Member   posted 06-10-98 10:41 AM
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Phenylacetaldehyde can be used for an easy method to make ----:
1)make the imine between methylamine and phenylacetaldehyde by refluxing equimolar amounts of the chems in toluene, collecting the water in a Dean-Stark trap. Distill of the toluene and distill the imine.

2)prepare methylmagnesium Grignard in ether by adding methyliodide to a magnesium/ether solution.

3)Add the imine, dissolved in a little ether, dropwise to the methylmagnesium Grignard (1.5 equivalents). After the addition, bring the mixture to reflux. Decompose the Grignard with NH4Cl... after standard workup you should have a good yield of ----.

I can remember someone else posting this variant, so if that someone could please come and get the credit for it! I only post this because I happened to be reading refs about this method and think this is a better purpose for your phenacetaldehyde. Lr/

Labrat
Member   posted 06-10-98 10:51 AM
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While searching under "phenylacetaldehyde" in the Lycaeum I ran into the ref you want. It's on Rhodium's page, but I've included the URL:
[url]http://www.lycaeum.org/~rhodium/chemistry/ch3i-p2p.txt[url/l].
I hope this helps. Lr/

Labrat
Member   posted 06-10-98 10:51 AM
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While searching under "phenylacetaldehyde" in the Lycaeum I ran into the ref you want. It's on Rhodium's page, but I've included the URL:
[url]http://www.lycaeum.org/~rhodium/chemistry/ch3i-p2p.txt[url/l].
I hope this helps. Lr/

Labrat
Member   posted 06-10-98 10:53 AM
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Damn, it's supposed to be like this: http://www.lycaeum.org/~rhodium/chemistry/ch3i-p2p.txt

Labrat
Member   posted 06-10-98 10:53 AM
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Damn, it's supposed to be like this: http://www.lycaeum.org/~rhodium/chemistry/ch3i-p2p.txt

Piglet
Member   posted 06-10-98 11:18 AM
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Thanks for the swift reply, LR. I'm not too crazy about using CH3I but it is an interesting route. I wonder if the bromide would work ?
I shall do some reading!
All the best,
Piglet:

Piglet
Member   posted 06-10-98 11:18 AM
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Thanks for the swift reply, LR. I'm not too crazy about using CH3I but it is an interesting route. I wonder if the bromide would work ?
I shall do some reading!
All the best,
Piglet:

Rhodium
Administrator   posted 06-10-98 08:58 PM
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Labrat: The refs to your imine method? Write up a more exact method than the one you posted, and include the refs, and I'll post it on my page.
According to my references, the reaction between Na hypochlorite and phenylalanine is called Strecker degradation, as opposed to the the Strecker amino acid synthesis from the aldehyde and ammonium cyanate. It seems like it is possible to get quantitative yield of phenylacetaldehyde from phenylalanine using hypochlorite if one checks out a few references - http://www.beilstein.com (Netfire) gave these among others:

Bull.Chem.Soc.Jpn., 54(7) 2057-2060 (1981)
Z. Naturforsch. B Anorg. Chem. Org. Chem., 36(3) 359-361 (1981)

Could somebody please look into this? It seems promising.

Rhodium
Administrator   posted 06-10-98 08:58 PM
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Labrat: The refs to your imine method? Write up a more exact method than the one you posted, and include the refs, and I'll post it on my page.
According to my references, the reaction between Na hypochlorite and phenylalanine is called Strecker degradation, as opposed to the the Strecker amino acid synthesis from the aldehyde and ammonium cyanate. It seems like it is possible to get quantitative yield of phenylacetaldehyde from phenylalanine using hypochlorite if one checks out a few references - http://www.beilstein.com (Netfire) gave these among others:

Bull.Chem.Soc.Jpn., 54(7) 2057-2060 (1981)
Z. Naturforsch. B Anorg. Chem. Org. Chem., 36(3) 359-361 (1981)

Could somebody please look into this? It seems promising.

Labrat
Member   posted 06-11-98 09:58 AM
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Piglet - ofcourse you can substitute methyl iodide for methyl bromide, but this latter chemicals is a gas at room temp and as such not so easy to handle. And since you use only 1.5 equivalents of methylmagnesium reagent I think methyl iodide is a viable option.
Rhodium - ofcourse I'd like to take credit for this method. But I thought I'd seen something posted like this a while ago. I think it was in a discussion on making ---- from Grignards. I've done a quick search on the Lycaeum. but could only find RatHead & your method on making P2P from phenylacetaldehyde. Your much better in searching old posts then I am & I have little time, cuz I'm posting my method to Strike today, so if you please could do a quick search. If it turns up empty, I'll be happy to take credit for the method. I will provide the refs, BUT I want to be sure I haven't ripped off anything from anybody. Cuz that's not the way it works around here. Lr/

Labrat
Member   posted 06-11-98 09:58 AM
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Piglet - ofcourse you can substitute methyl iodide for methyl bromide, but this latter chemicals is a gas at room temp and as such not so easy to handle. And since you use only 1.5 equivalents of methylmagnesium reagent I think methyl iodide is a viable option.
Rhodium - ofcourse I'd like to take credit for this method. But I thought I'd seen something posted like this a while ago. I think it was in a discussion on making ---- from Grignards. I've done a quick search on the Lycaeum. but could only find RatHead & your method on making P2P from phenylacetaldehyde. Your much better in searching old posts then I am & I have little time, cuz I'm posting my method to Strike today, so if you please could do a quick search. If it turns up empty, I'll be happy to take credit for the method. I will provide the refs, BUT I want to be sure I haven't ripped off anything from anybody. Cuz that's not the way it works around here. Lr/

Rhodium
Administrator   posted 06-11-98 10:33 AM
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Write something up, and I'll smack it up - if some bee feels that she wants her name on the paper too, then fine, she may write to me.
Even if the idea was someone elses, it is after all you who retrieved the ref and wrote the synth outline. Add a little disclimer at the top that you found the idea at The Hive. As long as all the ideas are publicly available, I think it doesn't matter THAT much WO wrote this and that.

Rhodium
Administrator   posted 06-11-98 10:33 AM
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Write something up, and I'll smack it up - if some bee feels that she wants her name on the paper too, then fine, she may write to me.
Even if the idea was someone elses, it is after all you who retrieved the ref and wrote the synth outline. Add a little disclimer at the top that you found the idea at The Hive. As long as all the ideas are publicly available, I think it doesn't matter THAT much WO wrote this and that.