| Number | Date | Country | Kind |
|---|---|---|---|
| 2321330 | Apr 1973 | DT |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3174997 | Campbell | Mar 1965 |
| Entry |
|---|
| Stevens et al., J. Amer. Chem. Soc., vol. 80, pp. 2759-2762, (1958). |
| Hofmann et al., Imidazole and Its Derivatives, Part I, pp. 127-131, N.Y., Interscience, 1953. |