| abstract |
NEW MATERIAL:A compound of formula I (R 1 is H or a protecting group of the carboxyl group; R 2 is aryl or heterocyclic group having a substituent group; R 3 is haloalkyl, aminoalkyl or alkenyl, etc.) and a salt thereof. n EXAMPLE: 6-(4-Chlorophenyl)-1-(4-fluorophenyl)-4-oxo-1,4-dihydronicotinic acid. n USE: An antimicrobial agent, capable of acting effectively on Gram-positive and Gram-negative bacteria, particularly exhibiting a powerful antimicrobial activity against germs resistant to antibiotic substances and having a high concentration in blood and high safety. n PREPARATION: A compound of formula II (R 8 is a protecting group of the carboxyl group) is subjected to ring closure reaction under heating to give a 4-oxo- 1,4,5,6-tetrahydronicotinic acid derivative of formula III, which is then dehydrogenated with a dehydrogenating agent, e.g. 2,3-dichloro-5,6-dicyano-p-benzoquinone, to afford the aimed compound of formula I . n COPYRIGHT: (C)1985,JPO&Japio |