Heterocyclic compounds as antagonist of NMDA

A compound represented by the formula (I):

• wherein
• ring A is a 6-membered aromatic ring substituted by a —CN group and a
• group, wherein the —CN group is meta relative to the
• group;
• ring A is further substituted by 1 to 4 substituents selected from
• (1) a C1-3 alkyl group,
• (2) a C1-3 haloalkyl group,
• (3) an optionally substituted cyclic group,
• (4) an optionally substituted C1-6 alkoxy group, and
• (5) a halogen atom;
• R1 and R2 are each independently a hydrogen atom or a C1-3 alkyl group optionally substituted by fluorine atom(s);
• R3 is
• (1) a group represented by
• wherein
• R4 is a substituent selected from
• (1) a C1-3 haloalkyl group,
• (2) an optionally substituted C3-7 cycloalkyl group, and
• (3) an optionally substituted C1-6 alkoxy group,
• Y is a nitrogen atom or CR6,
• R6 is a hydrogen atom or a halogen atom, and
• Z is a hydrogen atom or a halogen atom, or
• (2) a group represented by
• wherein
• R5 is a substituent selected from
• (1) a C1-3 haloalkyl group,
• (2) an optionally substituted C3-7 cycloalkyl group, and
• (3) an optionally substituted C1-6 alkoxy group, and
• ring B is a thiophene ring optionally further substituted by one halogen atom, or a salt thereof.