A method for the synthesis of the title compound [i.e., garenoxacin, 1-cyclopropyl-8-(difluoromethoxy)-7-[(1R)-2,3-dihydro-1-methyl-1H-isoindol-5-yl]-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid] is reported here. Alkylation of (1R)-5-bromo-1-methyl-1H-isoindole gave (1R)-5-bromo-2,3-dihydro-1-methyl-2-(triphenylmethyl)-1H-indole. A subsequent reaction of that compound with boron triisopropoxide gave [(1R)-2,3-dihydro-1-methyl-2-(triphenylmethyl)-1H-isoindol-5-yl]boronic acid. -, condensation and deprotection. A further reaction of this intermediate with 7-bromo-1-cyclopropyl-8-(difluoromethoxy)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid gave a protected garenoxacin intermediate. Deprotection delivered the target compound (51.0% overall yield). Product structures were determined by NMR, elemental anal., IR, MS. This method avoids the use of expensive reagents, provides the target compound in a few steps, and may have industrial applications.