The Vespiary

The Hive => Chemistry Discourse => Topic started by: politoxicomania on November 07, 2003, 11:21:00 PM

Title: 2-CMT 1H-NMR DATA
Post by: politoxicomania on November 07, 2003, 11:21:00 PM

Ok  here is what i found:

For d,l Carbomethoxytropinone i found a wonderful NMR spectrum.  2-CMT in d6Aceton shows following peaks:
strong singulett at 1.650 mixed with aceton at 1.655
strong duplett at 2.000
singulett at  3.200
another strong singulett at 6.00
there are much impurities  but a specifical  triplett with 4J coupling is observed at 4.5

Anyone out ther who have Lit. about NMR data ?

Title: good estimate generated with ChemOffice 2004
Post by: pHarmacist on November 20, 2003, 04:37:00 AM

Anyways I generated this with the afro-mentioned software, hope it throws some light on whatever the problem is...

(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000469518-file_omec.jpg)

Title: good compared to what?
Post by: Rhodium on November 20, 2003, 08:38:00 AM

good estimate

I'd say that estimate sucks - you get the correct number of peaks and the approximate splitting of the peaks, but you will seldom get the peak's more than within ±1 ppm accuracy using ChemOffice.

Title: was refering to the output: Estimation ...
Post by: pHarmacist on November 20, 2003, 01:21:00 PM

was refering to the output:

Estimation Quality: blue = good, magenta = medium, red = rough

Title: 2-Carbomethoxy-3-tropinone Proton NMR
Post by: Rhodium on November 20, 2003, 02:10:00 PM

That's what the program says, but compare that to the actual experimentally determined literature values:

(R)-(+)-2-Carbomethoxy-3-tropinone Proton NMR, Identical for the (S)-(-)-isomer.
Ref: J. Med. Chem. 37, 2001-2010 (1994)

¹H-NMR (100 MHz, CDCl₃) (https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000469518-file_ovss.gif) 1.5-2.4 (m, 7H), 2.32 (s, 3H), 2.75 (m, 1H), 3.32 (t, 1H), 3.75 (s, 3H).

Title: Great Compound but not 2-CMT
Post by: politoxicomania on November 20, 2003, 07:39:00 PM

To pharma.... : Look at your Molecule u postet above..
is it 2-carbomethoxitropinone ??
No!

I also have gNMR and Chem office and i dont want these computed spectrums cause they are unbelievable in respect to the keto-enol tautomerie.

to rhodium: can u please make the above mentioned artikle viewable cause i have no possibility to get this medical journal in our chemical bib.

thanks in advance....

Title: :)
Post by: pHarmacist on November 21, 2003, 04:37:00 PM

For Carbomethoxytropinone i found a wonderful NMR spectrum. [Bla.. Bla.. Bla..]

To pharma.... : Look at your Molecule u postet above..
is it 2-carbomethoxitropinone ??
No!

;D

Title: 1-H-NMR at 200MHz of pure 2-CMT in D2O
Post by: politoxicomania on May 06, 2004, 09:11:00 PM

After purification of 2-CMT (several sublimations at 1*10E-3mbar) i found this:

(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000469518-file_qhei.jpg)

Semms to be mainly the keto - form.
After a week the solution turned yellow, but no more NMR-spektra.... sorry

Title: I've seen 200 MHZ NMR spectra that were much...
Post by: _mu_ on May 07, 2004, 12:30:00 AM

I've seen 200 MHZ NMR spectra that were much cleaner. IIRC, at 200 MHz, you can see splittings of 5+ HZ. You sure didn't overconcentrate your sample?

Title: CHNS analyse
Post by: politoxicomania on May 07, 2004, 06:37:00 PM

N = 7,33%
C = 61,07%
H = 7,66 %

The solution was very low concentration as u can see much H2O in relativly new D2O.

I think that ther are 90% of the Keto -form  and only 10%enol-form .