Hexafluoroacetylacetone

[Chandresh K. Soni]

Hi,

I analyzed the Hexafluoroacetylacetone on GC and get all the impurities well separated.
My problem is during Rx. Monitoring we got the Peaks of intrest but after work up the peak will disappear in sample.
this compound have the tendency to prepare polyols with reacting with water. and this polyols is not soluble in dichloromethane. but this material is easily soluble in Methanol and Methyltertiarybutyl ether.
due to Presence of -OH functional i tried it on wax , innowax , column and also tried it on 5% phenyl stationary phase(db-5 or AT-5).
but i can't got the peaks. Can anybody tried it on this compound or is this compound easily analysis by GC.

[Don_Hilton]

I am not entirely clear on your question. If I understand correctly: While running a reaction you find a number of chromatographic peaks in the reaction mixture. After working up the reaction, you do not find all the peaks.

Without any further details of how you are handling the samples from the reaction mixture (I assume injecting the reaction mixture directly into the GC?) and what happens during workup (where the desired product is separated, at least to some extent, from other stuff) it is hard to guess what is going on. The first question that comes to mind is: are these compunds being lost in the workup?

[Chandresh K. Soni]

Dear Don,
During Rx. ( Liquid )I got the peak of Material after completion of Rx. we added water to convert it in hydrate form which is Solid and not soluble in Dichloromethane.
We got the solid material from Rx. Mixtute which is highly soluble in Methanol and Methyl tertiary butyl ether.
I want to analyse this material on GC but after two or three various column.
now i got the Peak on GC with injector Temp. 90°C and oven temp. at 40°C with Hydrogen as carried gas.
at higher injector temp. this material againe converted in the HFAAc.

thanks againe Don, also if u have some idea about this analysis please share with me.

regards
Dr.Chandresh k.Soni

[Don_Hilton]

It sounds like you have discovered that you can get a peak for the hexafluoroactoacetone by injecting the solution into a hot inlet. So beyond identifying that the desired compund is present, what do you need to know from the analysis. If it is purity of the product, that could be tricky by GC given that you have do decompose the hydrate in the GC inlet.

My thoughts go to Proton and Fluorene NMR - and looking for stray signals.

[Chandresh K. Soni]

Thanks Don,
This is not an discovery. my aim is only to analyze this compound by GC with FID Column which can help us to monitoring the Rx. during synthesis or during commercial production.

thanks Again

chandresh