S. Zhao et al., Phenanthridone analogs of the opiate agonist U-47,700 in the trans-1,2-diaminocyclohexane benzamide series, HETEROCYCLE, 52(1), 2000, pp. 325-332
The first rigid analog of the opioid <(trans)under bar>-1,2-diaminocyclohex
ane benzamide template was prepared. This analog represented by compound (4
b), in a phenanthridone analog of the mu agonist U-47,700 which, historical
ly, was the forerunner of the kappa acetamide U-50,488.