Methods of converting cannabidiol to .DELTA..sup.8-tetrahydrocannabinol or .DELTA..sup.9-tetrahydrocannabinol are described. The described methods produce higher yields and higher purity compared to prior art methods.
G. R. Barrie Webster, Leonard P. Sarna, Raphael Mechoulam
A method of converting cannabidiol (CBD) to .DELTA..sup.9-tetrahydrocannabinol (.DELTA..sup.9-THC) comprising: providing a reaction mixture comprising CBD in drymethylene chloride
adding BF.sub.3Et.sub.2O to the reaction mixture
stirring the ice cold reaction mixture under a nitrogen atmosphere
adding NaHCO.sub.3 to the reaction mixture
allowing the mixture to separate into an aqueous phase and anorganic phase
removing the organic phase
washing the organic layer with water
and eluting .DELTA..sup.9-THC from the organic phase, purity of the eluted .DELTA..sup.9-THC being greater than 97%.
The method according to claim 1 including stirring the reaction mixture for approximately 1 hour. (0)
The method according to claim 1 including drying the organic phase over MgSO.sub.4 and evaporating the organic phase following washing. (0)
The method according to claim 1 including eluting the organic phase on an HPLC column.
The method according to claim 4 wherein the .DELTA..sup.9-THC is eluted with ether in petroleum ether following washing the column with petroleum ether.
The method according to claim 5 wherein the ether in petroleum ether is 2 parts ether in 98 parts petroleum ether. (0)
The method according to claim 1 including eluting the organic phase on an RP-HPLC column. (0)