The purpose of the present invention is to provide: a compound having anti-HBV activity or a salt thereof； a pharmaceutical composition； an anti-hepatitis B virus agent； a DNA generation inhibitor of a hepatitis B virus； and a hepatitis B surface antigen generation or secretion inhibitor. According to the present invention, provided are a compound or a salt thereof, the compound being represented by general formula [1] (in the formula, R1 represents a substitutable benzothiazolyl group (here, carbon atoms constituting a 6-membered ring of the benzothiazolyl of R1 bond to the nitrogen atom of a pyridine ring)； R2 represents a substitutable C2-6 alkenyl group or the like； and R3 represents a hydrogen atom or the like).
