All Notebooks | Help | Support | About
25th March 2014 @ 01:15

Repeat of JU 1-1 for synthesis of key starting material.

Reaction Scheme

Procedure

Started 4pm

2,6-Dichloropyrazine (Aldrich, 5.005 g, 33.6 mmol) was dissolved in ethanol (50 mL) to give a clear solution. Hydrazine hydrate (1.75 mL, 1.7 g, 34 mmol) was added dropwise resulting in a pale yellow solution. The resulting mixture was heated at reflux (bath temperature 80˚C) for 19 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 19 h.jpg

Hydrazine hydrate (0.88 mL, 0.9 g, 18 mmol) was added to the solution and stirred for 1 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 20 h.jpg

The reaction was stirred for a further 1 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 21 h.jpg

The reaction was stirred for a further 5 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 26 h.jpg

Hydrazine hydrate (0.88 mL, 0.9 g, 18 mmol) was added to the solution and stirred for a further 16 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 42 h.jpg

The reaction was stirred for a further 8 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 50 h.jpg

The reaction was stirred for a further 16 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 66 h.jpg

The bath temperature was increased to 90oC and the reaction was stirred for 7 h. Analysis by TLC showed the reaction was incomplete.

TLC JU 1-3 70:30 EtOAc:Hex 73 h.jpg

Hydrazine hydrate (1.75 mL, 1.7 g, 34 mmol) was added to the solution and stirred over the weekend. Analysis by TLC showed a third spot.

TLC JU 1-3 70:30 EtOAc:Hex 1 wk.jpg

The reaction was cooled down and the solvent was evaporated by rotary evaporation and dried in vacuo. The crude product was a mixture of dark brown and yellow colours.

1H NMR, crude, CDCl3, 200 MHz

JU 1-3 crude CDCl3 200 MHz.pdf
JU 1-3 crude CDCl3.zip

 

HIRAC & Risk Assessment

See JU 1-1

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
Reaction Scheme JU 1-3.png
TLC JU 1-3 70:30 EtOAc:Hex 20 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 21 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 26 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 19 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 42 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 73 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 66 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 50 h.jpg
TLC JU 1-3 70:30 EtOAc:Hex 1 wk.jpg
JU 1-3 crude CDCl3 200 MHz.pdf
JU 1-3 crude CDCl3.zip
Comments