US 7,321,047 B2
Separation of tetrahydrocannabinols
Jason Edward Field, Mississauga (Canada); Jan Oudenes, Aurora (Canada); Boris Ivanovich Gorin, Oakville (Canada); Ricardo Orprecio, Etobicoke (Canada); Fabio Eduardo Silva e Souza, Mississauga (Canada); Navindra Jainarine Ramjit, Hamilton (Canada); and Emma-Louise Moore, Mississauga (Canada)
Assigned to Alphora Research Inc., Mississauga, Ontario (Canada)
Filed on May 19, 2005, as Appl. No. 11/132,251.
Prior Publication US 2006/0264647 A1, Nov. 23, 2006
Int. Cl. C07D 311/80 (2006.01)
U.S. Cl. 549—390 12 Claims
 
1. A process of separating an individual tetrahydrocannabinol isomer of interest from a mixture containing two or more such isomers, which comprises: treating the mixture with an isocyanate or isothiocyanate of formula I:
R—(CH2)n—N═C═X
where R represents an aromatic ring optionally substituted with one or more electron withdrawing groups, with the proviso that R is not 3,5-dinitrophenyl n=0 or 1 and X is oxygen or sulphur; so as to produce a crytallizable THC compound of formula II:

OG Complex Work Unit Drawing
wherein X, n and R are as defined above, R′ is a C3-C10 alkyl group and the dotted lines indicate optional unsaturation; forming a solution of the compound of formula II so formed in an organic solvent; separating the compound of formula II by crystallization from the solution in isolation of other THC derivatives; and hydrolyzing the compound of formula II to form the individual tetrahydrocannabinol isomer of interest.