Preparation of TriH(ethynyl)benzene (DEPROTECTION METHOD)

Tri(TMS)ethynylbenzene ---------------> Tri(H)ethynylbenzene
NaOH
DCM/MeOH

1. starting material are dissolved in DCM
2. NaOH are dissolved in MeOH (*refer calculation given)
3. mix 1 and 2

*mass of NaOH = (mol of starting mat. x JMR NaOH)4

PURIFICATION STEPS

• take the reaction mixture to dryness
• dissolve the residue in DCM, wash with small amout of water
• the two layers obtained are separated in a separatory funnel
• dry the organic phase layer over MgSo4
• then, filter it using filter paper
• the volume was reduced to ~10 ml
• the product was then purified using column chromatography (follow the previous purification steps for Tri(TMS)ethynylbenzene)
• the collected orange and yellow band are subjected to rotavapor
• NMR characterization

NOTES!!

Percentage yield obtained was 114% which indicates that the product obtained contains impurities.

It might resulted from unefficiency skills of separation (trace amount of catalyst and foreign matter may still remain).

NMR proves that some peaks due to grease and at 3.797ppm (still not sure due to what compound) are present.

However, NMR clearly shows that the product obtained is the true compound.