Wednesday

It's finally the day where my synthesis can finally be completed!

With 4 hours still remaining, I did a TLC test to see what was the progress if the reaction.

After spotting the silica gel paper with the 2 reactants and the product, and placed in jar with 4:1 Pet.ether : Ethyl acetate, dried and placed in UV light, the product line still had reactants' spots and also extra 6 more colourful spots.

This is a problem because i'm suppose to be obtaining one product only, hence there should be extra one spot only.

Also, something i forgot to mentioned. yesterday I performed a TLC around 12pm. The Product showed 3 spots that does not corrolate with the spots in reactants 1 and 2. My advosor told me it was probably because the product is still its formation process.

After my break, finally I was given the green light by my advisor to stop the stirring process and continue with stopping the reaction by acidifying the mixture with 10% HCl (acidity tested with PH paper-orange version), then washed with EtOAc (ethyl acetate), poured in seperating funnel, organic layer separated, aqueous layer washed with EtOac, EtOAc separated from aqueous layer and mixed into organic layer. Organic layer washed with brine, seperated again, MgSO4 added to organic layer, organic layer filtered.

The product was evaporated under pressure, and I noticed that right after the broen syrup cools to room temperature, the syrup crystallizes to yellow/orange cloudy crstals. Heating up the crystal with some EtOAc will dissolve the crystals back to the brown syrup. (did this twice!)

Then I had to prepare for column chromatography. A column (slightly bigger than what i used in uni, but still smaller compared to the humongous column another friend of mine was using). Cotton wool was added, to block the stationary phase from escaping. Poured some PET ether (4-6). Then added about 50g of silica (had to wear face mask all the time, these silicas fly everywhere!!) with Pet.ether slurry.

(accidentally spilt some of the slurry, so had to wait until the pet.ether evaporates and had to use a feather duster to dust away the silica that was on my desk, my books, my other apparatuses, my arms, everywhere!)

Conditioning the stationary phase: Let 200mL of Pet.ether run down the column until the eluent's surface levels above the silica surface.

Then it was time to add the sample. As I said, the sample had turned to cystals. And so my advisor, did the same thing as I did (adding solvent and doing rotatory evaporation). But this time, the sample stayed as syrup for a longer while, but we could see that it was hardening to cystals, so she sucked the syrup with a long pasteuer pippete and added the sample into teh column, but some portion of the syrup tuned into crystals and some of the sample left in the container had also turned to crystal I.E Percentage yield will be low!

100mL of pet.ether was added to the column, and eluent was allowed to run for sometime until yellowish colour eleunt reached the middle of the stationary phase.

That's where I collected a portion of the eluent as it drips through the column with a capillary tube and spotted on a silica gel paper and the spot was observed under the UV light. This was done every 5-10 minutes. If a spot is visible under the UV light, means there's presence of compound, meaning then I could start collecting the eluent with the 80 test tubes that I had already washed, dried and prepared!

And by the end of the day, I had collected 3 test tubes of eluent with very very very diluted sample, so diluted, it would be very hard to see under the UV light.