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

Participants

Reaction Steps

(RS)-1-Cyclopropyl-3-ethoxycarbonyl-7,9-difluoro-4-oxo-8-(3-phenyl-1-piperazinyl)-1,4-dihydrobenzo[b][1,8]naphthyridine was prepared under the conditions of Example 19, but starting with 1-cyclopropyl-3-ethoxycarbonyl-7,8,9-trifluoro-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine (1.8 g) and (RS)-2-phenylpiperazine (3.2 g). After recrystallization in a mixture of dimethylformamide (5 cc) and ethanol (40 cc), (RS)-1-cyclopropyl-3-ethoxycarbonyl-7,9-difluoro-4-oxo-8-(3-phenyl-1-piperazinyl)-1,4-dihydrobenzo[b][1,8]naphthyridine (1.8 g) is obtained in the form of a yellow solid, m.p. 242° C.

Provenance & Evidence