ritalin.

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:84276
http://www.hmdb.ca/metabolites/HMDB0014566
http://www.genome.jp/dbget-bin/www_bget?drug:D04999
http://www.genome.jp/dbget-bin/www_bget?cpd:C07196
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=4158
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46505929
https://www.chemspider.com/Chemical-Structure.4015.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=50062912
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=6901
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=84276
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL796
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DAP000024
http://www.pharmgkb.org/drug/PA450464
http://www.rxlist.com/cgi/generic/methphen.htm
https://www.drugs.com/methylphenidate.html
http://www.pdrhealth.com/drug_info/rxdrugprofiles/drugs/rit1383.shtml
https://en.wikipedia.org/wiki/Methylphenidate