Prepn and analgesic activity: W. B. Wright, Jr. et al., J. Am. Chem. Soc. 81, 1518 (1959); W. B. Wright, Jr., H. J. Brabander, US 3016382 (1962 to Am. Cyanamid). (-)-Phenampromid(e), the more active enantiomer, has the R-configuration. Absolute configuration: Portoghese, J. Med. Chem. 8, 147 (1965). Pharmacology: Kikuchi et al., Nippon Yakurigaku Zasshi 57, 585 (1961), C.A. 59, 2082b (1963). Determn by HPLC: I. Jane, A. McKinnon, J. Chromatogr. 323, 191 (1985).