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09-06-2016, First step in synthesis of the hetero-oxadiazole, reaction of 2-6 dichloropyrazine with malononitrile, following procedure from Nikishkin et al (2013)
09-11-2016, Work up of the second attempt at step 1
09-23-2016. Step 1 redo, on 5 gram scale
09-24-2016. Work up of 09-23-2016
09-29-2016, work up and purification of [4]
09/28/2016 Step 4, on a larger scale this time. Conversion of methyl 6-chloropyrazine-2-carboxylate [3] to methyl 6-hydrazineylpyrazine-2-carboxylate [4] using hydrazine according to AEW 85-5
10/07/2016 GC mass spec characterization of rxn from [4]->[5]
10/18/16: Trial work up of reaction of 6-chloropyrazinecarbonitrile and hydrazine
10/4/16: Trial of Step 4:Product [4] to Product [5]
10/6/16: Trial Synthesis of 6-hydrazinelypyrazine-2-carbonitrile and from 6- hydrazinelypyrazine-2-carboximidhydrazide from chloropyrazinecarbonitrile
9/12/16 Step 2 in synthesis. Going from [2]->[3]
9/13/16: Work-up of product [3] and TLC plates
9/15/16: Second Synthesis of Methyl 6-chloropyrazine-2-carboxylate [product 3]
9/18/16-9/20/16: Trial Synthesis of Methyl 6-hydrazineylpyrazine-2-carboxylate (Product 4)
9/22/16: Inconclusive Trial Synthesis of Methyl 6-hydrazineylpyrazine-2-carboxylate (Product 4)
9/25/16-9/27/16: Synthesis of Product 3, methyl 6-chloropyrazine-2-carboxylate
9/27/2016 Late Night
9/29/2016 HNMR of product 4, and HNMR of product 4 after D2O exchange 01/10/2016
9/8/16-Continued Synthesis of 2-(6-chloropyrazin-2(1H)-ylidene)malononitrile
CNMR so far
HNMR so far, of all relevant compounds
The Synthetic scheme of Hetero-oxadiazole Synthesis
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6th October 2016 @ 17:51

HNMR was taken of product 4. Product 4 was dried over high vac and was in the flask as a very thin layer of crust, so it was nearly impossible to scrape out. A sample for NMR was taken by pipetting in 0.5 mL CDCl3, dissolving produt 4 from the flask, then pipetting that into a vial and adding an additional 0.5 mL CDCl3. 

HNMR was taken

[4]big2.jpeg
 and irregularities were noted: notably, contaimation with EtOAc, the aromatic protons giving 3 signals instead of 2, and the NH protons not integrating for 3 protons. 

To attempt to resolve this, a proton exchange was performed with 2 drops D2O and shaking the NMR sample.  

d2oshake2.jpeg
After this shake, the NH protons dissappeared as expected, proving that the peaks initially assigned were correct. We still had the 3 signals for the aromatic protons, but because we had such an excellent 3:1 ratio of those protons to the methyl ester proton, we decided that the spectrum was clean enough to continue. Note that a new peak grows in in the D2O shake spectrum, but we jusge it to be insegnificant because it only grows in after the D2O is added, which only occured in that one vial.
Attached Files
[4]big2.jpeg
d2oshake2.jpeg