The Hetero Ring Contains At Least Eight Members Including Nitrogen And Carbon Patents (Class 540/450)
- Heavy metal, aluminum, boron or silicon containing (Class 540/452)
- Spiro (Class 540/453)
- Chalcogen in the hetero ring (Class 540/454)
- Plural nitrogens in the hetero ring (Class 540/460)
- Polycyclo ring system which contains the hetero ring as one of the cyclos (Class 540/461)
- Nitrogen or additional chalcogen attached directly to the hetero ring by nonionic bonding (Class 540/463)
- Utilizing oximes, oxime salts, hydroxylamines, hydroxylamine salts or nitrosating agents to form the hetero ring (i.e., formation of the lactam ring) (Class 540/464)