All Notebooks | Help | Support | About
3rd February 2014 @ 04:22

Repeat of AEW 85-1 (for scale up of key starting material).

Reaction complete, crude yield of 1.29g. Product used as starting material in JU 2-1. Note that the yield is >100%. Could be water, NMR does not show any unexpected peaks from impurities. 

Reaction Scheme

Procedure

Started 4:10pm

2,6-Dichloropyrazine (Aldrich, 1.014 g, 6.810 mmol) was dissolved in ethanol (10 mL) to give a clear solution. Hydrazine hydrate (0.33 mL, 340 mg, 6.8 mmol) was added dropwise resulting in a pale yellow solution. The resulting mixture was heated at reflux (bath temperature 80˚C) for 18 h. Examination of the reaction by TLC (2-3 drops of reaction mixture mixed with ethyl acetate and water (50:50), run vs. 2,6-dichloropyrazine in 50:50 ethyl acetate and water, TLC run in ethyl acetate and hexane (30:70)) under UV light showed residual starting material.

TLC JU 1-1.jpeg


Hydrazine hydrate (0.1 mL, 3 mmol) was added and the reaction was stirred for a further 1.5 h. Analysis by TLC (same conditions as above) showed that more starting material had reacted.

TLC JU 1-1 take 2.jpeg


The sample was concentrated under reduced pressure and in vacuo to yield an orange solid (1.29 g) that was examined by 1H NMR spectroscopy.

1H NMR, 200 MHz, crude, CDCl3.
Consistent with the desired product (see 1H NMR at AEW 85-1)and no trace of impurities present, aside from water peak. Spectrum of 2,6-dichloropyrazine starting material also taken for comparison.

JU 1-1 crude.pdf
JU 1-1 crude.zip

2,6-dichloropyrazine SM for JU 1-1.pdf
JU 2,6-dichloropyrazine.zip

Yield of 131%, 116% if product is hydrate.


HIRAC

Risk Assessment Sheet JU 1-1.pdf
HIRAC JU 1-1.pdf


InChI strings

InChI=1S/C4H2Cl2N2/c5-3-1-7-2-4(6)8-3/h1-2H

to

InChI=1S/C4H5ClN4/c5-3-1-7-2-4(8-3)9-6/h1-2H,6H2,(H,8,9)

SMILES

ClC1=CN=CC(Cl)=N1

to

ClC1=CN=CC(NN)=N1

Linked Posts
This post is linked by:
Attached Files
Risk Assessment Sheet JU 1-1.pdf
HIRAC JU 1-1.pdf
Reaction Scheme JU 1-1.png
JU 1-1 crude.zip
JU 1-1 crude.pdf
TLC JU 1-1 take 2.jpeg
TLC JU 1-1.jpeg
2,6-dichloropyrazine SM for JU 1-1.pdf
JU 2,6-dichloropyrazine.zip
Comments