The starting raw material for the synthesis of lignocaine (also known as lidocaine) is 2,6-Xylidine. This compound undergoes a series of reactions to form the final anesthetic compound.
A dipeptide, “x”, on complete hydrolysis gives “y” and “z”; “y” on treatment with aqueous HNO$_2$, produces lactic acid. On the other hand, “z” on heating gives the following cyclic molecule.
Based on the information given, the dipeptide X is: