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15th July 2016 @ 16:46

Reaction Scheme: 

 

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BS-1-1 (2-chloro-6-hydrazineylpyrazine, 2.00 g, 13.8 mmol) was stirred into a solution of 200 proof ethanol (50 mL).

4-(difluoromethoxy)benzaldehyde (2.40 g, 13.8 mmol) was added and the reaction mixture was stirred at room temperature for one hour. Reaction was monitred with TLC and starting material had not yet reacted. About 0.25g of p-toluenesulfonic acid was added to jumptstart reaction. TLC indicated a small amount of conversion so mixture was heated gently to reflux and left overnight. TLC shows that reaction did not go to completion.  

TLC:

Run in 70:30, EtoAC: Hexanes,

S: starting material

A: 4-(difluoromethoxy)benzaldehyde

C: co-spot of all three

P: product

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Attached Files
15th July 2016 @ 16:19

Rxn Scheme.png

2,6-dichloropyrazine (5 g) was dissolved in EtOH (67 mL, 0.50 M 3 %), and hydrazine (2.1 mL, 2 eq) added. The reaction mixture was stirred at reflux for 16 hours.

The solvent was removed under reduced pressure. Water (60 mL) and EtOAc (~75 mL) were added, and the mixture was shaken in an attempt to dissolve all solid. The organic layer was removed and the aqueous layer was washed 3 times with EtOAc.

An insoluble brown solid was filtered off and aqueous layer was washed 3 times with EtOAc.  The organic phases were combined, solvent was removed under reduced pressure, and the yellow solid was dried over vacuum to give  3.95g /4.85 g = 81.4% yield.

 

Water impurity and slight ethyl acetate impurity observed in NMR.  GC-MS indicates high level of purity.

Attached Files