| # | Country | Total Patents | |
|---|---|---|---|
| #1 | Switzerland | 10 | |
| #2 | Austria | 4 | |
| #3 | Germany | 3 | |
| #4 | Denmark | 2 | |
| #5 | France | 2 | |
| #6 | United Kingdom | 1 |
| # | Industry | |
|---|---|---|
| #1 | Organic fine chemistry |
| # | Technology | |
|---|---|---|
| #1 | Heterocyclic compounds |
| # | Name | Total Patents |
|---|---|---|
| #1 | Nederlandsche Kininefabriek N | 10 |
| Publication | Filing date | Title |
|---|---|---|
| GB454526A | Process of preparing halogenated phenanthrolines | |
| DE693090C | henanthroline series | |
| DE673063C | Process for the preparation of compounds of the m-phenanthroline series | |
| DE667543C | Process for the production of chloro- or bromine-m-phenanthrolines |