| abstract |
NEW MATERIAL:A 5,8-dihyrofuro or 2,3,5,8-tetrahydrofuro[ 3,2-b ]1,8-naphthyridine-7-carboxylic acid derivative (salt) shown by the formula I (R is H or lower alkyl). n EXAMPLE: 5, 8-Dihyro-5-( 2-hydroxyethyl )-8-oxofuro[ 3, 2-b ]1, 8-naph-thyridine- 7-carboxylic acid(salt). n USE: An antibacterial agent, a remedy for microbism, especially for uropathy. n PROCESS: For example, a compound shown by the formula II is formula II is heated with a dialkylformamide dialkyl acetal and a secondary amine to give an enamino compound, which is heated in an alcohol in the presence of an inorganic acid, e.g., hydrobromic acid, etc. to give an acetal derivative shown by the formula III. This derivative is treated with a Lewis acid, e.g., conc. sulfuric acid, etc. to give a furo[3,2-b]1,8-naph-thyridine derivative shown by the formula IV, and, if necessary, hydrolyzed and subjected to catalytic reduction. n COPYRIGHT: (C)1982,JPO&Japio |