Claims for Patent: 4,359,578

Summary for Patent: 4,359,578

Title:	Naphthyridine derivatives and salts thereof useful as antibacterial agents
Abstract:	This invention relates to 1,8-naphthyridine compounds of the formula ##STR1## wherein X is a halogen atom especially fluorine atom, R.sub.1 is an ethyl group or a vinyl group, and R.sub.2 is a hydrogen atom or a lower alkyl group, their salts and processes for the preparation of them. The 1,8-naphthyridine compounds and their salts are useful as antibacterial agents and intermediates thereof.
Inventor(s):	Matsumoto; Jun-ichi (Takatsuki, JP), Takase; Yoshiyuki (Amagasaki, JP), Nishimura; Yoshiro (Neyagawa, JP)
Assignee:	Dainippon Pharmaceutical Co., Ltd. (Osaka, JP) Laboratoire Roger Bellon (Neuilly sur Seine, FR)
Application Number:	06/068,966
Patent Claims:	1. A 1,8-naphthyridine compound of the formula ##STR31## or a nontoxic pharmaceutically acceptable salt thereof. 2. A salt according to claim 1 which is a hydrochloride or methanesulfonate. 3. 1-Ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridine-3 -carboxylic acid. 4. 1-Ethyl-6-fluo ro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-1,8-naphthyridine-3-carboxylic acid methanesulfonate.