1,5-Dioxa-9-azaspiro(5.5)undecane → 7-(1,5-Dioxa-9-azaspiro[5.5]undec-9-yl)-6-fluoro-1-(2,4-difluorophenyl)-1,8-naphthyridine-3-carboxylic acid

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Reaction Steps

In a reaction similar to that of Step 1, Example 387, into oven-dried glassware maintained under dry N2 were placed 0.622 g (3.96 mmol) of 1,5-dioxa-9-azaspiro[5.5]undecane, from Step 4 Example 196, 0.500 g (1.3 mmol) of 7-chloro-6-fluoro-1-(2,4-difluorophenyl)-1,8-naphthyridine-3-carboxylic acid ethyl ester, and 15 mL of dry pyridine. The reaction was stirred at room temperature for 5 hours, then the solvent was removed by evaporation. The residue was dissolved in 50 mL of methylene chloride, which was washed with 50 mL of 5% sodium bicarbonate and 50 mL of water, dried over anhydrous sodium sulfate, filtered and dried. The product was purified by recrystallization from ethanol/water, isolated by filtration and dried under vacuum to afford 0.576 g of the title compound, mp 177°-178° C., MS (DCl/NH3) M/Z 504 (M+H) (base). Analysis calculated for C25H24F3N3O5 : C, 59.64; H, 4.80; N, 8.35. Found: C, 61.13; H, 5.09; N, 8.36.

Provenance & Evidence