Piperazine → HCID 20063308, compound

Participants

Reaction Steps

The 3-ethoxycarbonyl-7,9-difluoro-4-oxo-8-(1-piperazinyl)-1-tert.-butyl-1,4-dihydro-benzo[b][1,8]naphthyridine was prepared under the conditions of Example 35, but starting from 1.9 g of 3-ethoxycarbonyl-7,8,9-trifluoro-4-oxo-1-tert.-butyl-1,4-dihydro-benzo[b][1,8]naphthyridine and 4.3 g of piperazine. After recrystallizing once from 50 cm3 of diisopropyl ether and 10 cm3 of propan-2-ol, 2 g of 3-ethoxycarbonyl-7,9-difluoro-4-oxo-8-(1-piperazinyl)-1-tert.-butyl-1,4-dihydro-benzo[b][1,8]naphthyridine are obtained in the form of a yellow solid melting at 186° C.

Provenance & Evidence