Structurally related to benzimidazole anthelmintics. Prepn and anthelmintic activity: M. M. Nafissi-Varchei, BE 840945; US 4006242 (1976, 1977 both to Schering). Physical data, activity against roundworms: E. Panitz et al., Experientia 34, 733 (1978). Anthelmintic effect against gastrointestinal parasites in naturally infected horses: J. H. Drudge et al., Am. J. Vet. Res. 41, 1383 (1980); E. T. Lyons et al., ibid. 42, 1048 (1981).