2-Methylpiperazine → (RS)-1-cyclopropyl-3-ethoxycarbonyl-7,9-difluoro-8-(3-methyl-1-piperazinyl)-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine

Participants

Reaction Steps

The (RS)-1-cyclopropyl-3-ethoxycarbonyl-7,9-difluoro-8-(3-methyl-1-piperazinyl)-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine was prepared under the conditions of Example 35 but starting from 1.8 g of 1-cyclopropyl-3-ethoxycarbonyl-7,8,9-trifluoro-4-oxo-1,4-dihydro-benzo[b][1,8]naphthyridine and 2 g of (RS)-2-methylpiperazine. After recrystallizing once from 15 cm3 of propan-2-ol and 15 cm3 of diisopropyl ether, 1.9 g of (RS)-1-cyclopropyl-3-ethoxycarbonyl-7,9-difluoro-8-(3-methyl-1-piperazinyl)-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine are obtained in the form of a yellow solid melting at 190° C.

Provenance & Evidence