temperature for 40 minutes at this point the mixture was treated with nh 4 oh 50 ml and ice 10 g and the mixture stirred at 0 u00b0 5 u00b0 c for 1 hour the chcl 3 layer was separated and the aqueous layer saturated with nacl and re extracted with chcl 3 3 u00d7 50 ml followed by ethyl acetate after washing the combined organic solutions were dried mgso 4 filtered and concentrated to give 272 mg of crude v free base the crude product was chromatographed over silica gel using chcl 3 and graded meoh chcl 3 as eluant to give 153 mg of purified product whose structure was confirmed by tlc and nmr at this point the product was taken up in ethanol 10 ml and 3 ml of concentrated hcl was added whereupon the solvent was removed via a rotary evaporator toluene was added and the solvent removed again additional toluene and ethanol were added and the solution evaporated to a dry solid which was taken up in methanol filtered and the filtrate concentrated to some extent ethyl acetate was added followed by drops of diethyl ether and 102 mg of solid product was obtained after filtration and drying to provide the title compound v which was assigned the code number 179 a 20 the structure of this material i e the hydrochloric acid addition salt of the compound prepared as described in the preceding paragraph was confirmed by mass spectral and elemental analysis the compounds whose preparation is disclosed in the foregoing examples were screened to determine the following biological activities b narcotic antagonist activity in rats modified rat tail flick test the analgesic effects of test compounds were determined.