like this?
On paper it'd be stable at least for a little bit, but I'd expect it to hydrolise to ritalinal (? aldehyde form of ritalinic acid) pretty quick, faster than a methyl ester would.
Pharmcology wise I think it'd be close to MPH.
Things like this have been tested. Swapping the piperidine for a morpholine was the best example. The 2,6 dioxine can be e benzene (or p-Me benzene) so you can get serotonin action without the v.long T1/2. Illegal in UK, not sure about elsewhere.