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6th November 2017 @ 15:18

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Masses and measurements:

Hydrazone - 1.5054g, 4.84mmol

BAIB - 1.7038g, 5.29mmol

Dichloromethane - 30mL

Procedure:

The hydrazone product (1.5054g, 4.84mmol) was dissolved in a RBF using dichloromethane (30mL) whilst being stirred. Once the solid was fully dissolved, BAIB (1.7038g, 5.29mmol) was added to the reaction mixture  and the mixture was left to stir for 2-3 hours. The reaction mixture was a thick cloudy orange mixture and continued to look the same until the end of the reaction. Next the reaction was quenched by adding NaHCO3 (30mL) and the remaining solution was extracted and seperated using ethyl acetate (3x40mL). Next the retained organic layers were dried with MgSO4 and the precipitate was filtered out leaving behind the filtrate of organic layers which was subsequently rotary evaporated leaving behind an orange solid. The remaining solid was then seperated on a flash column (1:1 ethyl acetate & pet ether) where it was found that test tubes 1-17 contained the end product; these test tubes were combined, rotary evaporated and the product of 3-(4-bromophenyl)-5-chloro-[1,2,4]triazolo[4,3,a]pyrazine (0.5854g, 39.13%) was formed as a pale orange crystal like solid. 

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Attached Files
6th November 2017 @ 10:34

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Masses andmeasurements:

4-bromobenzaldehyde - 2.0559g, 11.1mmol

2-chloro-6-hydrazinylpyrazine - 1.6399g, 11.3mmol

Ethanol - 25mL

Procedure:

4-bromobenzaldehyde (2.0559g, 11.1mmol) was dissolved in ethanol (25mL) and stirred in a RBF. Once the solid was dissolved in the ethanol, the 2-chloro-6-hydrazinylpyrazine (1.6399g, 11.3mmol) was slowly added to the stirring reaction mixture. The solution was colourless until the pyrazine was added, which was when the reaction mixture turned an orange foamy mixture. The mixture was stirred for a few hours until TLC analysis (70% pet ether & 30% ethyl acetate) suggested the reaction was complete. The resulting reaction mixture was filtered under vacuo, washed with ethanol and dried over air. The remaining solid product of (E)-2-(2-(4-bromobenzylidene)-6-chloropyrazine (3.2011g, 92.62%) was obtained as an orange powdery solid.

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Attached Files
5th November 2017 @ 20:45



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Masses and measurements:


Triazolopyrazine - 0.2061g, 6.64mmol

THF - 1.5mL

4-fluorophenyl ethan-1-ol - 0.16mL, 1.28mmol

NaH - 0.0291g, 1.21mmol

 

Procedure:

Triazolopyrazine (0.2061g, 6.64mmol) was added to THF (1.5mL) under an inert atmosphere and whilst stiriing. Still under an inert atmosphere, 4-fluorophenylethan-1-ol (0.16mL, 1.28mmol) was added to the stirring solution. Next the NaH (0.0291g, 1.21mmol) was added and the reaction mixture was put under ice and left to react for a few hours until TLC analysis (1:1 ethyl acetate & pet ether) confirmed the reaction was complete. The resulting solution was seperated using ethyl acetate,then dried with MgSO4. The precipitate was filtered out and the filtrate was rotary evaporated leaving behind the final product of 3-(4-bromophenyl)-5-(4-fluorophenethoxy)-[1,2,4]triazolo[4,3,a]pyrazine which was dark brown solid.

Attached Files