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Wednesday 6/2/2018

Oxidation of 1 to form 2 (AS07)

New attempt with very close supervision from fellow group member: In a round bottom flask, 67.7 mg of 1 was dissolved in 20 mL of DCM:ACN:water (9:1:1) with stirring. To this was added 20.6 mg of \(\ce{RuCl3}\), followed by 235.0 mg of \(\ce{NaIO4}\). The reaction mixture was heated to 40\(^\circ\)C and left for 3 hours.

TLC was taken to check the progress, and another 100 mg of \(\ce{NaIO4}\) was added and left overnight.

Reduction of 2 to form 3 (AS05)

Upon my supervisor’s instruction, we ran MS on the sample and did indeed find some 3 in there, however it must be in really low quantity to not show up in NMR. I’ve redissolved the sample in \(\sim\) 1 mL of DCM and am reducing it right down until it’s barely liquid, at which point, following 1, I will try and extract a product using n-hexane:ethyl acetate (5:1).

While adding the n-hexane:ethyl acetate didn’t cause anything to precipitate, when I added 3\(\times\) the amount of DCM on top of it and started evaporating it off (with increased airflow), a fine white precipitate started to fall out of solution (fig:AS05ppt). In trying to filter off the precipitate, vacuum filtering it was not successful, however I’ll try redissolving it in DCM and try crystallising the product out with straight n-hexane, instead of n-hexane:ethyl acetate to see what happens.


Precipitate forming from crude 3
So the process requires the ethyl acetate, but In thinking, it may be possible to reverse this process and dissolve the product in n-hexane and drip in ethyl acetate to try and crash out the product. I realised as well that the methodology I’m following is for a C8-NDI which will be slightly less polar than than the C6-NDI I’ve synthesised.

  1. o-quinodimethane