[Butyllithium]

Hi, everyone:
I'm having a trouble preparing trifluoromethyl group, which is attached to 2-position of substituted pyrimidine. In original proposal, trichloromethyl group will be transformed to trifluoromethyl group with HF condition, but failed. What about other methods?
Any help will be appreciated. Thanks and best regards.

Butyllithium

[russellm72]

Hi,

I've done this using sodium trifluoroacetate and CuI in NMP at 160 0C acting on the iodide.

You can also use trifluoroiodomethane but you have to distill this on a manifold as it's a gas but works nicely too in the presence of dry CuI.

The top one didn't go wonderfully but my substrate was a tad volatile and maybe doing it in a sealed tube under vacuum (of suitable size, do a pressure calculation) may be better.

If you put sodium trifluoroacetate and trifluoromethylation into a well known search engine I'm sure you'll get the paper which I can't find at present. If you can't get back to me and I'll dig further.

R.