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Topic: 1,2-dihydrocyclobutabenzene-1-carboxylic acid  (Read 3899 times)

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Offline vinodt

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1,2-dihydrocyclobutabenzene-1-carboxylic acid
« on: June 05, 2015, 03:03:13 AM »
Please help me for the preparation of 1,2-dihydrocyclobutabenzene-1-carboxylic acid

Offline billnotgatez

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #1 on: June 05, 2015, 04:46:43 AM »
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Offline orgopete

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #2 on: June 05, 2015, 06:25:49 AM »
Please help me for the preparation of 1,2-dihydrocyclobutabenzene-1-carboxylic acid

Is this a known compound (meaning it has been prepared before)?
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Offline vinodt

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #3 on: June 05, 2015, 09:53:35 AM »
billnotgatez: many thanks . for your rule guidelines

orgopete: Yes sir, the compound was reported and tried to prepare from 3-(2-bromophenyl)propanenitrile using Sodamide (as per literatures) but failed.

Offline orgopete

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #4 on: June 05, 2015, 10:07:16 AM »
What was supposed to happen and what happened?
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Offline pgk

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #5 on: June 05, 2015, 11:40:27 AM »
1). The synthesis of 1,2-dihydrocyclobutabenzene-1-carboxylic acid is described in:
The Journal of the American Chemical Society, 80(9), 2257–2263, (1958)
http://pubs.acs.org/doi/abs/10.1021/ja01542a055.
2). Alternatively and if it is difficult to obtain the experimental conditions for the Wolf rearrangement that is described therein, try a Favorskii rearrangement and starting by a previous α-halogenation of the appropriate benzo-(b)-cycloalkanone.
3). If you draw the corresponding reaction mechanism, you will understand that the preparation of 1,2-dihydrocyclobutabenzene 1- nitrile from 3-(2-bromophenyl) propanenitrile and sodamide, works well in case of an ortho- and/or para- electron attractive substitution to the bromine group. Otherwise, you need sodamide in liquid ammonia, through a cyclization reaction that occurs by a benzyne formation mechanism (sodamide is prepared in situ).
« Last Edit: June 05, 2015, 12:27:37 PM by pgk »

Offline vinodt

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #6 on: June 07, 2015, 12:20:43 AM »
orgopete:      Tried to prepare Cyclobutane -1-carboxylic acid but since the reaction was carried in liq. NH3 and it occurs through benzyne mechanism, amination takes place by knocking the halogen part.

pgk:

3. Yes I agree with you, I found lot of reports with ortho- and/or para- electron attractive substitution to the bromine group, but here I want to perform the reaction on 3-(2-bromophenyl)propanenitrile.

As you told, I'm performed the reaction in liq. NH3 only (sodamide is prepared in situ)

2. Thanks for your suggestion using favorskii, but my doubt is whether it work or not on aromatic species. Please suggest if any.

Offline orgopete

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #7 on: June 07, 2015, 09:03:04 AM »
Since it appears to be a lit prep (according to pgk), I am surprised by its failure. I'd have rated M. Cava quite highly. I don't have access to the journal, so I don't know the yields that were reported.

From your comment, the next logical step might be to use LDA. Diisopropylamine should be much less nucleophilic than amide/ammonia.
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Offline vinodt

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #8 on: June 08, 2015, 04:42:59 AM »
orgopete:  I have already attempted with LDA but it leads to multiple spots in TLC and no desired or any other characterized mass by LCMS, crude 1H NMR also didn't showed any of the required peaks.

Offline orgopete

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #9 on: June 08, 2015, 07:31:49 AM »
What yield did Cava report?
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Offline pgk

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Re: 1,2-dihydrocyclobutabenzene-1-carboxylic acid
« Reply #10 on: June 08, 2015, 01:37:14 PM »
1). I am wondering why not a 3-(2-(or 3)aminophenyl formation phenyl)propanenitrile formation and a further formation a five member condensed system or a simple  sodamide attack to the nitrile, instead of the formation of benzocyclobutanenitrile  with a high Bayer tension, in such reaction conditions?
2). Indeed aromatic haloketones do not easily lead to Favorskiĭ rearrangement:
“The Favorskiĭ Rearrangement of Haloketones,” Organic Reactions, Vol.  11, (1960), Published Online: 15 MAR 2011
3). However, an effiecient but  step consuming method could start from 3-(3- (or 5) –nitro, 2-bromophenyl)propanenitrile → product formation→ Nitro group reduction to amine→ deamamination by nitrite esters in DMF, in order to avoid Sandmayer deamination. Reductive deamination of arylamines by alkyl nitrites in N,N-dimethylformamide.
“Reductive deamination of arylamines by alkyl nitrites in N,N-dimethylformamide”.  A direct conversion of arylamines to aromatic hydrocarbons , J. Org. Chem, 42(22), pp 3494–3498, (1977)
« Last Edit: June 08, 2015, 02:02:40 PM by pgk »

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