Conversion of cbd to delta8-thc and delta9-thc

Abstract

Methods of converting cannabidiol to Δ 8 -tetrahydrocannabinol or Δ 9 -tetrahydrocannabinol are described. The described methods produce higher yields and higher purity compared to prior art methods.

1 . A method of converting CBD to Δ 8 -THC comprising:
 providing a reaction mixture comprising a Lewis acid in an organic solvent;   adding CBD to the reaction mixture;   refluxing said reaction mixture;   diluting the mixture with an organic solvent;   pouring the mixture into cold water;   mixing the mixture;   allowing the mixture to separate into an aqueous phase and an organic phase;   removing the organic phase; and   eluting Δ 8 -THC from the organic phase.   
     
     
         2 . The method according to  claim 1  wherein the reaction mixture is mixed under a nitrogen atmosphere. 
     
     
         3 . The method according to  claim 1  wherein the Lewis acid is p-toluenesulfonic acid in toluene. 
     
     
         4 . The method according to  claim 1  wherein the Lewis acid is boron trifluoride. 
     
     
         5 . The method according to  claim 1  wherein the Δ 8 -THC is eluted by HPLC. 
     
     
         6 . The method according to  claim 1  wherein the Δ 8 -THC is eluted by RP-HPLC. 
     
     
         7 . The method according to  claim 1  including washing the organic phase with aqueous NaHCO 3  prior to eluting. 
     
     
         8 . The method according to  claim 7  including drying the organic phase over MgSO 4  and evaporating the organic phase following washing. 
     
     
         9 . The method according to  claim 5  wherein the Δ 8 -THC is eluted with ether in petroleum ether. 
     
     
         10 . The method according to  claim 9  wherein the ether in petroleum ether is 5-10% ether in petroleum ether. 
     
     
         11 . The method according to  claim 6  wherein the Δ 8 -THC is eluted with water-methanol or water-acetonitrile.