11-07-03 23:21
No 469518
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 ?
(pHantasticant)
11-20-03 04:37
No 471875
Anyways I generated this with the afro-mentioned software, hope it throws some light on whatever the problem is...
http://www.bassdrive.com/BassDrive.m3u
(Chief Bee)
11-20-03 08:38
No 471907
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.
(pHantasticant)
11-20-03 13:21
No 471954
was refering to the output:
Estimation Quality: blue = good, magenta = medium, red = rough
http://www.bassdrive.com/BassDrive.m3u
(Chief Bee)
11-20-03 14:10
No 471966
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)
1.5-2.4 (m, 7H), 2.32 (s, 3H), 2.75 (m, 1H), 3.32 (t, 1H), 3.75 (s, 3H).
(Hive Bee)
11-20-03 19:39
No 472022
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....
(pHantasticant)
11-21-03 16:37
No 472260
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!
http://www.bassdrive.com/BassDrive.m3u
(Hive Bee)
05-06-04 21:11
No 505368
After purification of 2-CMT (several sublimations at 1*10E-3mbar) i found this:
Semms to be mainly the keto - form.
After a week the solution turned yellow, but no more NMR-spektra.... sorry
----
(Hive Bee)
05-07-04 00:30
No 505414
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?
(Hive Bee)
05-07-04 18:37
No 505615
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 .