3'-Hydroxy- and (+/-)-3',11-dihydroxy-delta 9-tetrahydrocannabinol: biologically active metabolites of delta 9-tetrahydrocannabinol.

Synthesis of 3'-hydroxy- (7) and (+/-)-3',11-dihydroxy-delta 9-tetrahydrocannabinol (11), metabolites of delta 9-THC, is described. Condensation of the monoterpene (+/-)-cis-p-menth-2-ene-1,8-diol (1) and (+/-)-3'-acetoxyolivetol (2) in the presence of fused ZnCl2 in CH2Cl2 gave a mixture from which the delta 9-THC derivative 3, containing small amounts of the delta 8-isomer 4, was isolated after column chromatography. This mixture was separated as their diacetates 5 and 6 by high-pressure liquid chromatography. Alkaline hydrolysis (5% KOH in MeOH) of 5 furnished the metabolite 7. Condensation of (+/-)-8 with 2 in the presence of p-toluenesulfonic acid gave 9a, which was acetylated to 9b. Treatment with HgO/BF3 X Et2O in wet THF gave the aldehyde 10. Reduction with LiAlH4 furnished the metabolite 11. These metabolites were compared with delta 9-THC for their ability to depress spontaneous activity and rectal temperature in mice and for their effects on overt behavior in dogs. 3'-Hydroxy-delta 9-THC was also compared to delta 9-THC in the mouse sympatomatology test and cardiovascular system in dogs. The metabolites produced pharmacological effects similar to those of delta 9-THC in all tests. 3'-Hydroxy-delta 9-THC was 2-3 times more effective than delta 9-THC in the behavioral tests, whereas (+/-)-3',11-dihydroxy-delta 9-THC was approximately 3 times less active than delta 9-THC.

Novel opiates and antagonists. 5. 7-Carbethoxy-N-(cycloalkylmethyl)-3-hydroxymorphinan-6-ones and -isomorphinan-6-ones.

A direct conversion of deoxydihydrothebaine-phi (1) to 3-methoxymorphinan-6-one (3Ca) and its trans isomer 3Ta was achieved in excellent yield by the catalytic reduction of 1 in AcOH containing CF3COOH. Treatment of 3Ca or 3Ta with NaH and diethyl carbonate formed the corresponding 7-carbethoxy derivatives 4a which, on O-demethylation, furnished the 3-hydroxy compounds 4b. The analgesic N-methyl compounds 3 were converted to the 17-(cyclopropylmethyl) or 17-(cyclobutylmethyl) derivatives 6--8. Two of these compounds, one in the cis (7Ca) and the other in the trans (7Ta) series, showed mixed agonist/antagonist activity in the pentazocine range.

(-)-4-Hydroxymorphinanones: their synthesis and analgesic activity.

A facile procedure is described for the conversion of morphine, via the diphosphate ester derivative 1 followed by catalytic reduction and treatment with Li/NH3, to 3-deoxy-7,8-dihydromorphine (3). Oxidation with benzophenone tert-butoxide converted 3 to the ketone 4, which on treatment with Zn/NH4Cl formed (-)-4-hydroxymorphinan-6-one 5. Reaction of 5 with diazomethane formed the methyl ether 6. The N-cyclopropylmethyl analogues of 4 and 5 were also prepared, i.e., 8c and 9 from 4. The antinociceptive activity of these compounds was tested. Compounds 5, 6, 8c, and 9 showed potent antiwrithing activity and, based on these data, a structure-activity relationship in morphinans is discussed.

Hashish. Unsaturated side-chain analogues of delta8-tetrahydrocannabinol with potent biological activity.

Two delta8-THC derivatives, 4a and 4b, with functionalized side chains were synthesized. Treatment of (+)-trans-p-mentha-2,8-dien-1-ol with the resorcinal 2b followed by removal of the dithiol group with HgO--BF3-Et2O gave the aldehyde 3b. A Wittig reaction of dimethyl (2-oxoheptyl)phosphate with 3b furnished 4a, which was reduced to 4b. Compounds 4a and 4b showed potent cannabinoid-like activity in mice.

Drugs derived from cannabinoids. 3. Sulfur analogs, thiopyranobenzopyrans and thienobenzopyrans.

Sulfur analogs of cannabinoids corresponding to DMHP (1) were prepared utilizing the Pechmann condensation between the appropriate keto ester and (5-(1,2-dimethylheptyl)resorcinol, followed by Grignard reaction. Compounds of various structural types (2-6), which had different ring size and position of the sulfur atom substituted in the alicyclic ring, were found to be active CNS agents in pharmacological tests in mice, rats, and dogs. They showed profiles qualitatively similar to those of the nitrogen and carbocyclic analogs. Basic esters of the most interesting parent phenols 2 and 4 were also prepared and tested.

Drugs derived from cannabinoids. 4. Effect of alkyl substitution in sulfur and carbocyclic analogs.

Various CNS-active cannabinoids in which the alicyclic ring was thiopheno, cyclopenteno, or cyclohexeno with the alkyl substituent in various positions (structural types 1-6) were synthesized by procedures described previously. These compounds were compared in selected pharmacological tests in mice, rats, dogs, and cats. The results suggested that methyl substitution in the close proximity of the phenolic hydroxyl group strongly influenced the activity of some cannabinoids, particularly of those which had a planar five-membered alicyclic ring rather than a six-membered ring.

Potential central nervous system antineoplastic agents. Amides of 6-cyano-6-norlysergic acid.

A group of amides of 6-cyano-6-norlysergic acid was prepared from their corresponding lysergamides. None of these N-cyano derivatives showed anticancer activity against lymphoid leukemia L1210 in mice. This is in contrast to the reported in vitro anticancer activity (P-815 mastocytoma) of 6-cyano-6-norlysergic acid diethylamide.

Hashish. Importance of the phenolic hydroxyl group in tetrahydrocannabinols.

Optically active delta-3- and delta-8-tetrahydrocannabinols (THC's), cannabidiol and racemic delta-9-cis-THC, and their corresponding analogs (1b yields 4b) in which the positions of the phenolic hydroxyl group and the n-C5 side chain have been interchanged are compared in selected pharmacological tests in mice. the results indicate that the phenolic hydroxyl group in the 1 position in THC's is very important for eliciting activity and that cannabidiol and delta-9-cis-THC possess weak CNS depressant properties.

Water-soluble derivatives of 1 -tetrahydrocannabinol.

Delta1-Tetrahydrocannabinol, which is resinous and insoluble in water and therefore difficult to study pharmacologically, can be converted to a watersoluble derivative without loss of its biological activity. This has been achieved by preparing esters bearing a nitrogen moiety with the use of carbodiimide as the condensing agent. The availability of such water-soluble derivatives will allow the evaluation of Delta1-tetrahydrocannabinol in self-administration studies in monkeys for its addiction liability potential in man. This technique of water solubilization is also applicable to other compounds of chemical and biological significance.