4-n-Butyl-3-(3-methyl­phen­yl)-1H-1,2,4-triazol-5(4H)-one

In the mol­ecule of the title compound, C13H17N3O, the two rings make a dihedral angle of 56.63 (13)°. Mol­ecules are linked by strong N—H⋯O inter­molecular hydrogen bonds into chains running along the c axis