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

Participants

Reaction Steps

(RS)-3-Ethoxycarbonyl-7,9-difluoro-8-[3-(4-fluorophenyl)-1-piperazinyl]-1-methyl-4-oxo -1,4-dihydrobenzo[9 [1,8]naphthyridine was prepared under the conditions of Example 39, but starting with 3-ethoxycarbonyl-7,8,9-trifluoro-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine (2 g) and (RS)-2-(4-fluorophenyl)piperazine (4 g). After 1 recrystallization in a mixture of dimethylformamide (3.5 cc) and ethanol (31.5 cc), (RS)-3-ethoxycarbonyl-7,9-difluoro-8-[3-(4-fluorophenyl)-1-piperazinyl]-1-methyl-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine (2.1 g) is obtained in the form of a beige solid, m.p. 242° C.

Provenance & Evidence