The title mol-ecule, C(13)H(18)N(2)O(3), contains a benzene ring fused to an oxazine ring and one tert-but-oxy-carbonyl group bound to the N atom of the oxazine ring. A weak intra-molecular C-H⋯O inter-action occurs. In the crystal, inter-molecular N-H⋯O and C-H⋯O hydrogen bonds stack the mol-ecules down the b axis. Weak C-H⋯N contacts connect the stacks, generating a three-dimensional network.