Chemical Forums
1 Hour
1 Day
1 Week
1 Month
Forever
December 23, 2024, 02:27:40 AM
Forum Rules
: Read This Before Posting
Home
Help
Search
Login
Register
Chemical Forums
Chemistry Forums for Students
Organic Chemistry Forum
Organic Chemistry Forum for Graduate Students and Professionals
Methylation product
« previous
next »
Print
Pages: [
1
]
Go Down
Topic: Methylation product (Read 6664 times)
0 Members and 1 Guest are viewing this topic.
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Methylation product
«
on:
August 23, 2015, 12:49:06 AM »
Dear guys.
i would like to ask regarding my work. I did my reaction and and the column chromatography gave me three fractions . For fraction 1 and 2 the NMR are just fit enough. But i have problem
for the fraction 3.
From NMR, all the signal compatible to the structure A. Somehow during writing the mechanism it does seems not make sense otherwise i suggest the structure B as the product.
Could anyone give a suggestion regarding this matter.tq
Logged
phth
Chemist
Full Member
Posts: 528
Mole Snacks: +39/-4
Re: Methylation product
«
Reply #1 on:
August 23, 2015, 04:34:54 AM »
May sound simple, but I would take an IR or #3. Secondly, I would try this procedure K
3
PO
4
+18-crown-6 instead of NaOH. DOI: 10.1021/ie060899e Ind. Eng. Chem. Res. 2007, 46, 3016-3023
«
Last Edit: August 23, 2015, 07:47:10 AM by phth
»
Logged
Dan
Retired Staff
Sr. Member
Posts: 4716
Mole Snacks: +469/-72
Gender:
Organic Chemist
Re: Methylation product
«
Reply #2 on:
August 24, 2015, 02:04:38 AM »
I can't think of a reasonable mechanism for the oxidative dimer you posted.
It would help if post your NMR spectra, do you have MS?
Logged
My research:
Google Scholar
and
Researchgate
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #3 on:
August 24, 2015, 02:29:22 AM »
I only have NMR spectrums and have not do the MS analysis yet due to the instrument problem.
I attach here 1H, 13C and DEPT NMR spectrum. I have done HMQC and it just good enough to fit my structure-assumption of fraction 3(A).
tq for your concern.
Logged
Dan
Retired Staff
Sr. Member
Posts: 4716
Mole Snacks: +469/-72
Gender:
Organic Chemist
Re: Methylation product
«
Reply #4 on:
August 24, 2015, 03:24:44 AM »
I have an idea of what it is. I could be wrong, but:
Hint 1: Start by adding the enolate form of your starting material to the keto form of your starting material
Hint 2: I think the formula of the product is C
23
H
22
N
2
O
3
Logged
My research:
Google Scholar
and
Researchgate
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #5 on:
August 24, 2015, 04:08:04 AM »
I loss one O group?
Logged
Dan
Retired Staff
Sr. Member
Posts: 4716
Mole Snacks: +469/-72
Gender:
Organic Chemist
Re: Methylation product
«
Reply #6 on:
August 24, 2015, 07:34:31 AM »
Yes I think so (dehydration).
Logged
My research:
Google Scholar
and
Researchgate
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #7 on:
August 24, 2015, 11:09:31 AM »
yes i have tried to suggest the structure as a lactone unit and also in a spiro compound, but it seems none of it works.
Logged
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #8 on:
August 25, 2015, 12:46:43 AM »
ok now i think i got the structure. But please correct me if i am wrong. It is quite close to the NMR of the chemdraw expectation.
Logged
Dan
Retired Staff
Sr. Member
Posts: 4716
Mole Snacks: +469/-72
Gender:
Organic Chemist
Re: Methylation product
«
Reply #9 on:
August 25, 2015, 02:33:09 AM »
Yes, that's what I think it is - via aldol condensation followed by methylation.
Logged
My research:
Google Scholar
and
Researchgate
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #10 on:
August 25, 2015, 02:48:26 AM »
ok thanks a lot Mr Dan for the help. I am gonna run GC-MS within this two days to confirm it. I will update the result.
very much appreciate of your help.
Logged
pallidol
Regular Member
Posts: 21
Mole Snacks: +0/-0
Re: Methylation product
«
Reply #11 on:
August 27, 2015, 05:14:37 AM »
i have done my GC-MS and there are several peak with the same molecular weight appear start from 28-30 minutes.
So I am pretty sure this is the structure. But somehow i am gonna analysis it using hr-ms within this two weeks.
«
Last Edit: August 27, 2015, 05:28:58 AM by pallidol
»
Logged
Print
Pages: [
1
]
Go Up
« previous
next »
Sponsored Links
Chemical Forums
Chemistry Forums for Students
Organic Chemistry Forum
Organic Chemistry Forum for Graduate Students and Professionals
Methylation product