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10th December 2014 @ 05:39

Resynthesis of SGS 1-1.

Reaction performed by Trent Wallis.

Reaction scheme for synthesis of 2-chloro-6-hydrazinylpyrazine

2,6-dichloropyrazine (20 g, 134 mmol) was suspended in 100 mL EtOH and hydrazine hydrate (14.5 mL, 270 mmol) added. The mixture was stirred under reflux overnight.  

Photos:

20 s after hydrazine addition

SGS-1-2-start.jpg
 

30 min after hydrazine addition

SGS-1-2-30min.jpg

55 min after hydrazine addition

SGS-1-2-55min.jpg

17.5 hours after hydrazine addition

IMG_20141211_120207.jpg

The ethanol was then removed from the crude mixture in vacuo at 60°C, giving an orange oil to which EtOAc (200mL) and  water (150mL) was added. The aqueous layer was removed and washed with EtOAc (3x 100mL). The combined EtOAc layers were concentrated in vacuo at 60°C to produce an orange oil that solidified upon slight cooling. 

The crude product was recrystallised from ethanol/water; 6.865 g of a crystalline orange solid were obtained.

Photos:

Product mixture after removing the ethanol

IMG_20141211_143658.jpg

Crude product after water wash, extraction into EtOAc and removal of EtOAc

IMG_20141211_163800.jpg

No, Mr Hydrazine, I expect you to die!

IMG_20141211_153503.jpg

Recrystallised product.

IMG_20141212_163808.jpg

TLC (3:7 EtOAc:hexane) revealed a new spot at Rf = 0.68, SM at Rf = 0.85).

IMG_20141212_170409.jpg

S = starting material, P = recrystallised product, Co = both S and P co-spotted.

Conclusion: Looks like some starting material is still present...

SMILES

ClC1=CN=CC(Cl)=N1 to

ClC1=CN=CC(NN)=N1

InChI

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)

Attached Files
SGS-1-2-start.jpg
SGS-1-2-30min.jpg
SGS-1-2-55min.jpg
IMG_20141211_120207.jpg
IMG_20141211_143658.jpg
IMG_20141211_153503.jpg
IMG_20141211_163800.jpg
IMG_20141212_163808.jpg
IMG_20141212_170409.jpg