Diazepane derivatives or salts thereof

A diazepan derivative represented by the following general formula (I) or a salt thereof:

• 173
• (symbols in the above formula have the following meanings:
• Rings A and B:
• they are the same or different and are each aryl or heteroaryl which may have 1 to 3 substituents;
• X1:
• —C(═O)—NR4—, —NR4—C(═O)—, —NR4—CH2—, —O—CH2—, —CH2—CH2— or —CH═CH—;
• X2:
• —C(═O)—NR5— or —NR5—C(═O)—;
• R1:
• hydrogen atom, lower alkyl, -lower alkylene-O-lower alkyl, C3-8 cycloalkyl, aryl, heteroaryl, -lower alkylene-C3-8 cycloalkyl, -lower alkylene-aryl, -lower alkylene-heteroaryl or —C(═NR6)-lower alkyl;
• R2:
• —OH, —O-lower alkyl, —O-lower alkylene-OH, —O—SO2—OH, —O-lower alkylene-COOH, —O-lower alkylene-COO-lower alkyl, —COOH, —COO-lower alkyl or halogen atom;
• R3:
• hydrogen atom, halogen atom or lower alkyl;
• and
• R4, R5 and R6:
• they are the same or different and are each hydrogen atom or lower alkyl.)