Synthesis and study on analgesic effects of 1-[1-(4-methylphenyl) (cyclohexyl)] 4-piperidinol and 1-[1-(4-methoxyphenyl) (cyclohexyl)] 4-piperidinol as two new phencyclidine derivatives.

Phencyclidine (1-(1-phenylcyclohexyl) piperidine; CAS 956-90-1; PCP, I) has shown analgesic effects. Some of its derivatives have been synthesized and their biological properties have been studied. In this work, new methyl and methoxy hydroxyl derivatives of phencyclidine were synthesized and the analgesic effects of this compounds [(1-[1-(4-methylphenyl) (cyclohexyl)] 4-piperidinol, II), (1-[1-(4-methoxyphenyl) (cyclohexyl)] 4-piperidinol, III)] were studied using tail immersion test on rats and compared to PCP. The results showed that, II can produce more analgesic effects in the tail immersion test (as a model of acute thermal pain) in comparison to the PCP with a marked significant increase in tail immersion latency (15, 40 and 45 min after injection) but for III, only slight analgesic effects (15, 35 and 40 min after injection) was seen (without significant differences between pain thresholds).