| Number | Name | Date | Kind |
|---|---|---|---|
| 3452032 | Grasselli et al. | Jun 1969 | |
| 4049727 | Gelfand | Sep 1977 |
| Number | Date | Country |
|---|---|---|
| 3101352 | Feb 1977 | JPX |
| 5013207 | Jul 1978 | JPX |
| 406820 | Aug 1971 | SUX |
| 703519 | Mar 1978 | SUX |
| Entry |
|---|
| Chemical Abstract, 75: P63494h, (Czech. 137,475). |
| Chemical Abstract 51: P5403, (U.S. 2,775,629). |
| Chemical Abstract 28: P2373, 28; P2732. |