Oxidation of pyridine derivatives can usually be effected very easily and in good yield and minimal difficulty with a peracid like meta-peroxybenzoic acid (mCPBA). Even I, a physical chemist, could manage it.
I don't have a procedure handy, but I bet if you search for oxidation of pyridine or bipyridine with mCPBA, you should be able to adapt a procedure to picoline pretty easily.
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Here's an older procedure. I'd use mCPBA instead of the reagent used there. It'll be much safer to handle.
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv4p0828