[Rosalind Franklin]

Hey guys!

I am trying to use ZnO nanoparticles(ZnO NPs) as catalyst for Coumarin synthesis. I tried Knoevenagel condensation under thermal conditions. I went with the literature and added salicylaldehyde, diethylmalonate and ZnO NPs but I am not getting any solid product. From what I know about Knoevenagel condensation, it requires a mild base which can abstract the acidic proton from diethylmalonate. Could lack of mild base be the reason for not getting any product?

[wildfyr]

I have not had recreating luck with those transition metal NP papers. I gave iron NPs a shot to do NO2 reduction and got classic glop. I think these reactions are quite sensitive to NP size, surface chemistry, etc.

[Rosalind Franklin]

I have not had recreating luck with those transition metal NP papers. I gave iron NPs a shot to do NO2 reduction and got classic glop. I think these reactions are quite sensitive to NP size, surface chemistry, etc.

Yes, I got some glop too! I tried using piperidine as my base and had no luck yesterday. I read somewhere that an excess of piperidine can make the product gooey. So, today I reduced the amount of piperidine and it worked! TLC looks good but I need to characterise further. Thanks a lot!

[wildfyr]

Awesome to hear your success story!

Care to share the paper you were following?

[Rosalind Franklin]

Yeah sure! This is the paper I referred to.
https://www.ias.ac.in/article/fulltext/jcsc/123/05/0615-0621

I also referred to a lab report on the synthesis of 3-Carbethoxycoumarin. Not a published work but I found it useful.
http://sites.psu.edu/timikeyi/wp-content/uploads/sites/10213/2014/02/Synthesis-of-3-Carbethoxycoumarin.docx