  The $D^*\bar{D}_1(2420)$ and $D\bar{D}'^*(2600)$ interactions are studied in
a one-boson-exchange model. Isovector bound state solutions with spin parity
$J^P=1^{+}$ are found from the $D^*\bar{D}_1(2420)$ interaction, which may be
related to the observed charged charmonium-like state $Z(4430)$. There is no
bound state solution found from the $D\bar{D}'^*(2600)$ interaction.
