[evie]

Hi,

I am using a N, N dimethylformamide dimethyl acetal (Me₂NCH(OME)₂ to protect a primary amine (it's a dmf protecting group actually) and I have digged up a couple of journals that synthesise the exact same compound that i am doing. All states that precipitate will occur, but i at most see a couldy suspension, after repeating it many times. Solvent used is methanol and after rotavaping dry my mixture, i see oil, which i suspect may be dmf. Hence, all i could do is to i column my compound out.

Most likely there's impurities in it. That's y ppt dun appear. But hw can i get e ppt to appear? Thanks!!!

cheerios,
evie

[GSR]

hi,

you can try by allowing your compound(in a sealed container)  to stand  overnight in a refrigerator.because  sometimes the precipitation may occur later than we expected.

cheers
GSR

[GSR]

oh ya! and if I am not wrong you might be using excess amount of methanol and thats why you are not able to see the precipitation.

[evie]

thanks..but i tried both method. rotavaping e methanol dry only works once...my latest trial...after n times...

[greengiant]

You might also try crashing it out by adding diethyl ether