| —— | 
                                        7-(1-tert-Butoxycarbonyl-cyclopropyl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        123821-76-1 | 
                                        C22H25FN2O5 | 
                                        416.449 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        7-(1-Carboxy-cyclopropyl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        123821-82-9 | 
                                        C18H17FN2O5 | 
                                        360.342 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        7-tert-Butoxycarbonylmethyl-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        123822-18-4 | 
                                        C20H23FN2O5 | 
                                        390.411 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        7-(1-Azidocarbonyl-cyclopropyl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        1025914-11-7 | 
                                        C18H16FN5O4 | 
                                        385.355 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        7-(1-Amino-cyclopropyl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        123822-07-1 | 
                                        C17H18FN3O3 | 
                                        331.347 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        7-(1-tert-Butoxycarbonylamino-cyclopropyl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid ethyl ester | 
                                        123822-03-7 | 
                                        C22H26FN3O5 | 
                                        431.464 |