1. 1) T. Nozoe, T. Mukai, and I. Murata: J. Am. Chem. Soc., 76 (1954) (in press).
2. 2) T. Nozoe, T. Mukai, K. Takase, I. Murata, and K. Matsumoto: Proc. Japan Acad., 29, 452 (1953).
3. 3) The microanalyses were carried out by Mr. Onoe of Sankyô Co. Ltd., and by Miss Katô of this laboratory, to whom the writers express their gratitude.
4. 4) T. Nozoe, M. Satô, S. Ito, K. Matsui, and T. Matsuda: Proc. Japan Acad., 29, 565 (1953).
5. 5) A new nomenclature is proposed for these new types of compounds. The name of “azulane” is given to “1, 2-dihydrazulene”. and consequently (Ib) may be named “1, 3-diazazulan-2-one”.