<p>?9 THC is obtained by extracting ?9 THC and ?9 THC carboxylic acid from plant material using a non-polar solvent and decarboxylating the ?9 THC acid into ?9 THC in the same solvent, without a solvent swap, in the presence of aqueous base. The ?9 THC is then washed to remove inorganic impurities, still in the same original solvent.</p>