| Number | Date | Country | Kind |
|---|---|---|---|
| 2639702 | Sep 1976 | DEX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3898179 | Beschke et al. | Aug 1977 | |
| 3917542 | Beschke et al. | Nov 1975 | |
| 3960766 | Beschke et al. | Jun 1976 | |
| 4171444 | Beschke et al. | Oct 1979 | |
| 4171445 | Beschke et al. | Oct 1979 | |
| 4175195 | Beschke et al. | Nov 1979 | |
| 4179576 | Miyake et al. | Dec 1979 |
| Number | Date | Country |
|---|---|---|
| 633266 | Dec 1949 | GBX |
| Entry |
|---|
| Breitmaier et al., "Tetrahedron Letters", No. 38 (1970), pp. 3291-3294. |
| Klingsberg Pyridine and Its Derivatives, Part One, Interscience, N.Y., pp. 498-500; 508 (1960). |