The present invention provides a novel compound having antiviral activity, especially HIV replication inhibitory activity and a medicament containing the same. The compound represented by the formula:wherein A3 is CR3A, CR3AR3B, N or NR3C； R3A, R3B, R4A and R4B are each independently a hydrogen atom, halogen, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkynyl, or substituted or unsubstituted non-aromatic carbocyclyl； R3C is a hydrogen atom, substituted or unsubstituted alkyl, or substituted or unsubstituted non-aromatic carbocyclyl； ring T1 is substituted or unsubstituted nitrogen-containing non-aromatic heterocycle； R1 is a hydrogen atom, halogen, cyano, or substituted or unsubstituted alkyl； R2 is each independently substituted or unsubstituted alkyl or the like: n is 1 or 2； R3 is substituted or unsubstituted aromatic carbocyclyl or the like； R4 is a hydrogen atom or a carboxy protecting group.
