Injectable hypnotic related to etomidate, q.v. Prepn: BE 662474; E. F. Godefroi, C. A. M. van der Eijcken, US 3354173 (1965, 1967 both to Janssen); E. F. Godefroi et al., J. Med. Chem. 8, 220 (1965). Anaesthetic effect of combination with azaperone, q.v.: J. F. F. Callear, J. F. E. Van Gestel, Vet. Rec. 92, 284 (1973); of combination with fentanyl, q.v.: W. Erhardt, J. Small Anim. Pract. 19, 401 (1978); C. J. Green, Lab. Anim. 15, 171 (1981).