| Number | Date | Country | Kind |
|---|---|---|---|
| 63-265662 | Oct 1988 | JPX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3775386 | Citron | Nov 1973 | |
| 3778430 | Citron | Dec 1973 | |
| 4118367 | Dawes et al. | Oct 1978 | |
| 4316041 | Totten et al. | Feb 1982 | |
| 4618653 | Kawakubo et al. | Oct 1986 |
| Entry |
|---|
| March, "Advanced Organic Chemistry", 3rd ed., John Wiley and Sons, New York 1985 pp. 791-792, 802-803. |