NEW MATERIAL: A compound of formula I (R1 is an amino having antibacterial activity; R2 is H, a lower alkoxy, a lower alkylthio, etc.; R3 is H or an organic group bonded via C, O, S or N; R4 is an electronegative acidic group, or R3 and R4 together form a heterocyclic ring; R5 is H, a lower alkyl, etc.) and its ester, salt, and hydrate.
EXAMPLE: [2S-(2α,5α,6β)]-6-[[[4-[1-ethyl-6-fluoro-1,4-dihydro-3-(methoxycarbonyl)-4- oxo-7quinolinyl]-1-piperazinyl]methylene]amino]-3,3-dimethyl-6-oxo-4-thia-1- azabicyclo[3,2,0]heptane-2-carboxylic acid.
USE: Treatment or prophylaxis of infectious diseases.
PROCESS: The compound of formula I can be obtained by reacting a compound of formula II or its ester with an acetal of formula R1-Rb (Rb is an acetal functional group) or its ester.
JIYON ROOSON ROBAATSU
CHIYUNNCHIEN UEI
