PROBLEM TO BE SOLVED: To provide a novel compound having an antiviral action, particularly an HIV replication inhibitory activity, and a medicament containing the same, particularly an anti-HIV drug. A compound of formula (I). (In the formula, A3 is CR3A, CR3AR3B, N or NR3C; R3A, R3B, R4A and R4B are independently hydrogen, halogen, cyano, substituted/unsubstituted alkyl, substituted/unsubstituted alkynyl, or substituted. -Unsubstituted non-aromatic carbocyclic group; R3C is hydrogen, substituted/unsubstituted alkyl, or substituted/unsubstituted non-aromatic carbocyclic group; ring T1 is substituted/unsubstituted nitrogen-containing non- Aromatic heterocycle; R1 is hydrogen, halogen, cyano, or substituted/unsubstituted alkyl; R2 is independently substituted/unsubstituted alkyl etc.: n is 1 or 2; R3 is substituted/unsubstituted Substituted aromatic carbocyclic group, etc.; R4 is hydrogen or a carboxy protecting group) [Selection diagram] None【課題】抗ウイルス作用、特にHIV複製阻害活性を有する新規化合物およびそれを含有する医薬、特に抗HIV薬を提供する。【解決手段】式(I)の化合物。(式中、A3は、CR3A、CR3AR3B、NまたはNR3C;R3A、R3B、R4AおよびR4Bは、独立して、水素、ハロゲン、シアノ、置換・非置換のアルキル、置換・非置換のアルキニル、または置換・非置換の非芳香族炭素環式基;R3Cは、水素、置換・非置換のアルキル、又は置換・非置換の非芳香族炭素環式基;環T1は、置換・非置換の含窒素非芳香族複素環;R1は、水素、ハロゲン、シアノ、又は置換・非置換のアルキル;R2は、独立して、置換・非置換のアルキル等:nは、1又は2;R3は、置換・非置換の芳香族炭素環式基等;R4は、水素又はカルボキシ保護基)【選択図】なし