| Number | Date | Country | Kind |
|---|---|---|---|
| 3907938 | Mar 1989 | DEX |
| Entry |
|---|
| Tetrahedron Report Number 92, Heteroannelations with o-Amino-aldehydes, Caluwe, vol. 36, pp. 2359-2407 (1980). |
| 1,8-Naphthyridines, Part II, Preparation and Some Reactions of 2-Substituted Derivatives, Hawes et al., J. Chem. Soc. (1967), pp. 1564-1568. |