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The synthesis of a variety of novel 10-substituted cannabidiol (CBD) and 11- or 12-substituted delta 8-tetrahydrocannabinol (delta 8-THC) analogues containing amino, alkylamino, azido, or a N,N-bis(2-chloroethyl)amino functional group is described, as well as their pharmacological evaluation in mice. These analogues, which possess only a portion of the full pharmacological spectrum of activity of delta 9-THC, indicate that cannabinoid-mediated reduction of spontaneous locomotor activity, hypothermia, antinociception, and/or catalepsy need not be produced simultaneously, possibly suggesting the existence of more than one mechanism of action. The 10-substituted CBD analogues 3, 4, and 5 with an ethylamino, propylamino, or azido functional group, respectively, proved to be largely inactive, except for the production of central nervous system (CNS) depression concomitant with toxicity. Toxicity and CNS depression may be related phenomena in these nitrogenous compounds since 12-amino and 12-ethylamino analogues (8 and 11) of delta 8-THC also proved to be very toxic. Antinociceptive and hypothermic responses (without reduction of motor activity) were observed at a dose of 10 mg/kg of the 11-ethylamino analogue (9) of delta 8-THC, while a dose of 50 mg/kg of the nitrogen mustard 11-[N,N-bis(2-chloroethyl)amino]-delta 8-THC (12) was necessary to produce any observable pharmacological effect. When selected analogues were evaluated for antagonistic properties, they failed to attenuate the effects of delta 9-THC. Some nitrogen mustard analogues were capable of producing minimal pharmacological effects after either peripheral or direct CNS administration; however, these analogues also failed to attenuate the effects of delta 9-THC either immediately after administration or 24-48 h later.

The title compounds were synthesized from cannabidiol in yields of 21% and 29% respectively.

Several C-10 substituted cannabidiol (CBD) derivatives and novel oxepin derivatives of delta 9-tetrahydrocannabinol (delta 9-THC) were synthesized and evaluated for biological activity in mice and dogs. Treatment of 10-bromocannabidiol diacetate (3) with various amines in Me2SO gave the corresponding 10-aminocannabidiol derivatives 4-6. Similarly, treatment of 3 with NaN3 gave the azido compound 7, which with LiA1H4 afforded the 10-aminocannabidiol 9. However, reduction of 7 with CrCl2 formed the amide 8, which on further reduction with LiA1H4 gave the N-ethyl analogue 10. Coupling of 9 with 11 in the presence of dicyclohexylcarbodiimide formed 12, which was then deprotected with HCl to give the analogue 13. The oxepin analogue 14a was synthesized from 3 by treatment with Na2CO3 in CH3OH/H2O at room temperature. The dimethylheptyl analogue 14b was similarly prepared. Incorporation of N-ethyl (10), N-methyl-N-propargyl (6), and morpholino (4) groups in CBD at position 10 resulted in analogues that were more potent than CBD in producing hypoactivity in mice. These analogues had relatively little effect on rectal temperature. Selected substitutions at C-10 also resulted in analogues that were partially effective in blocking delta 9-THC antinociceptive activity. This blockade was observed particularly in compound 10, which also showed unusually toxic properties. Incorporation of a seven-membered oxepin in the delta 9-THC structure eliminated cannabinoid activity although substitution of the pentyl side chain with a 1,2-dimethylheptyl in the oxepin 14b resulted in CNS depression in mice.