| 摘要 |
The present invention provides a compound which has the effect of PDE inhibition, and which is useful as a medicament for preventing or treating schizophrenia or so on. A compound of formula (I 0 ):
wherein
R 1 represents
a substituent,
R 2 represents
a hydrogen atom, or a substituent,
R 3 represents
a hydrogen atom, or a substituent,
Ring A represents
an aromatic ring which can be substituted, and
Ring B represents
a 5-membered heteroaromatic ring which can be substituted,
or a salt thereof. |
