2018¶

Reduction of 2 to form 3 (AS08) Attempt 2¶

The reaction mixture had turned from deep blue to pale yellow and was reduced under vacuum to $\sim$10 mL and diluted with another $\sim$30 mL of DCM. The pH was checked at this point and determined to be $\sim$7.5, so not was added. The mixture was then washed with water (2$\times$40 mL) and $\sim$5.4 M brine (2$\times$40 mL). It was then dried with $\ce{NaSO4}, filtered through celite and dried under vacuum, producing a yellow/white crude powder. The crude powder was redissolved in minimal DCM.

Water washing of AS08 During the water washing (

fig:AS08washing), an interesting solid formed in the interface between the organic and aqueous phases. I’m not entire sure what it could be, or if there’s anything in this reaction that could polymerise.

Reduction of 2 to form 3 (AS05)¶

In playing around with this, I came up with a procedure that seems to work to precipitate out 3, however the precipitate is so fine (fig:AS05ppt2) that extracting it is proving difficult. I’ve come up with a plan (see Next week’s plan) to precipitate and extract this using the skillset I’ve learned in biochemistry, of precipitating, centrifuging and washing.

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Precipitated 3 from AS05

Next week’s plan¶

Redissolve AS05 and AS08 in minimal DCM
Pipette AS05 and AS08 into microcentrifuge tubes
Dry the tubes till only 0.1 mL left
Add 1 mL of hexane:ethyl acetate (5:1)
Allow to precipitate
Centrifuge and pour off supernatant
Redissolve in 0.1 mL DCM in centrifuge tube
Add another 1 ml of hexane:ethyl acetate (5:1)
Allow to precipitate
Centrifuge and pour off supernatant
Pellet should now be pure 3