Structural Elucidation of Azo and Quinoneimine Products Formed in Diazonium-Based Color Reactions of Cannabinoids
Cannabis use is generally restricted worldwide because it contains the narcotic compound Δ<sup>9</sup>-tetrahydrocannabinol (Δ<sup>9</sup>-THC). Although cannabis is detected at crime scenes using color-based primary screening methods, the details of the reaction mechanism have not yet been elucidated. In this study, we isolated the products generated during the color reaction between the diazonium salt prepared from <i>para</i>-nitroaniline and nine cannabinoids and determined their structures. Azo compounds <b>6</b>, <b>11</b>, <b>16</b>, and <b>17</b> were produced from cannabidiol, cannabigerol, cannabichromene, and cannabidiolic acid, respectively, while quinoneimines <b>7</b>-<b>10</b> and <b>12</b>-<b>15</b>, which contained positional isomers, were produced from cannabinol, Δ<sup>9</sup>-THC, and hexahydrocannabinol. The reaction barely proceeded with Δ<sup>9</sup>-THC acetate and HHC acetate.
Authors
- Manabu Tokeshi (ORCID: https://orcid.org/0000-0002-4412-2144)
- Kyohei Higashi (ORCID: https://orcid.org/0000-0002-2622-4825)
- Hikari Nishiguchi
- Kayo Nakamura (ORCID: https://orcid.org/0000-0003-4577-060X)
- Akihiko Ishida (ORCID: https://orcid.org/0000-0003-4100-9426)
- Riho Hamajima
- Ryosuke Arai
- Hiroko Abe
- Hideyo Takahashi
- Akiyoshi Saitoh
Institutions
- Tokyo University of Science (JP)
- Hokkaido University (JP)
- Japan Institute of Wastewater Engineering Technology (JP)
Publication Details
- Journal
- Molecules
- Published
- 2026-02-27
- DOI
- https://doi.org/10.3390/molecules31050796
- Primary Topic
- Cannabis and Cannabinoid Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00