| Number | Date | Country | Kind |
|---|---|---|---|
| 2-92280 | Apr 1990 | JPX | |
| 2-93452 | Apr 1990 | JPX | |
| 2-93453 | Apr 1990 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2410407 | Dusland | Nov 1946 | |
| 4451471 | Ferrini et al. | May 1984 | |
| 4567267 | Wei et al. | Jan 1986 |
| Entry |
|---|
| D'Amico, J. Heterocyclic Chem. 24, pp. 945-948 (1987). |
| Sanfilippo et al., J. Med. Chem. 31, pp. 1778-1785 (1988). |