Methods for converting cbd to tetrahydrocannabinols

Abstract

This disclosure provides a method for converting CBD to a tetrahydrocannabinol featuring the use of cheap and non-toxic aluminum isopropoxide as a catalyst. The method comprises (a) providing a reaction mixture comprising a catalyst in an organic solvent, wherein the catalyst comprises aluminum isopropoxide; (b) adding a reagent comprising CBD to the reaction mixture; (c) mixing the reaction mixture and allowing a reaction for converting CBD to a tetrahydrocannabinol to occur for a predetermine period of time; (d) removing the catalyst by filtration upon the completion of the reaction; (e) removing the organic solvent; and (f) eluting the tetrahydrocannabinol from the organic phase.

What is claimed is: 
     
         1 . A method of converting CBD to a tetrahydrocannabinol, comprising:
 (a) providing a reaction mixture comprising a catalyst in an organic solvent, wherein the catalyst comprises aluminum isopropoxide;   (b) adding a reagent comprising CBD to the reaction mixture;   (c) mixing the reaction mixture and allowing a reaction for converting CBD to a tetrahydrocannabinol to occur for a predetermined period of time;   (d) removing the catalyst by filtration upon the completion of the reaction;   (e) removing the organic solvent; and   (f) eluting the tetrahydrocannabinol from the organic phase.   
     
     
         2 . The method of  claim 1 , wherein the tetrahydrocannabinol is Δ8-tetrahydrocannabinol (Δ8-THC). 
     
     
         3 . The method of  claim 2 , wherein the tetrahydrocannabinol is Δ9-tetrahydrocannabinol (Δ9-THC). 
     
     
         4 . The method of  claim 1 , wherein the yield of the tetrahydrocannabinol is at least 60%. 
     
     
         5 . The method of  claim 1 , wherein the yield of the tetrahydrocannabinol is at least 80%. 
     
     
         6 . The method of  claim 1 , wherein the yield of the tetrahydrocannabinol is at least 90%. 
     
     
         7 . The method of  claim 3 , wherein the ratio of Δ8-THC to Δ9-THC is between about 1:10 and about 10:1. 
     
     
         8 . The method of  claim 3 , wherein the ratio of Δ8-THC to Δ9-THC is between about 1:1 and about 6:1. 
     
     
         9 . The method  claim 3 , wherein the ratio of Δ8-THC to Δ9-THC is between about 2:1 and about 5:1. 
     
     
         10 . The method of  claim 1 , following mixing the reaction mixture, heating the reaction mixture to a temperature between about 70° C. and about 110° C. to allow complete mixing. 
     
     
         11 . The method of  claim 10 , comprising, following mixing the reaction mixture, the reaction mixture is heated to about 90° C. to allow complete mixing. 
     
     
         12 . The method of  claim 10 , wherein heating is stopped when the reaction mixture is substantially mixed. 
     
     
         13 . The method of  claim 1 , wherein the organic solvent comprises isopropyl. 
     
     
         14 . The method of  claim 1 , wherein removing the organic solvent is performed under a pressure near atmospheric pressure to a pressure substantially below atmospheric pressure. 
     
     
         15 . The method of  claim 1 , wherein mixing the reaction mixture is performed a nitrogen atmosphere. 
     
     
         16 . The method of  claim 1 , comprising eluting the tetrahydrocannabinol on an HPLC column. 
     
     
         17 . The method of  claim 1 , comprising eluting the tetrahydrocannabinol on an RP-HPLC column. 
     
     
         18 . The method of  claim 1 , wherein the tetrahydrocannabinol is eluted with water-methanol or water-acetonitrile. 
     
     
         19 . The method of  claim 1 , wherein the reagent further comprises a tetrahydrocannabinol. 
     
     
         20 . The method of  claim 19 , wherein the tetrahydrocannabinol is Δ9-THC.