HCID 57758693, compound → HCID 15604366, compound

Participants

Reaction Steps

The 7-[7-(tert-butoxycarbonylamino)-7-methyl-5-azaspiro[2.4]heptan-5-yl]-6-fluoro-1-[(1R,2S)-2-fluorocyclopropyl]-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (870 mg, 1.676 mmol) obtained in Reference Example 10 was dissolved in concentrated hydrochloric acid (10 mL) under cooling with ice, the mixture was stirred at room temperature for 20 minutes, and this reaction solution was washed with chloroform (20 mL, ×5). To the aqueous layer was added a saturated aqueous solution of sodium hydroxide under cooling with ice, thereby making the solution to have pH 12.0. Subsequently, this solution was adjusted with hydrochloric acid to have pH 7.4. After that, the organic layer was extracted with a mixed solution of chloroform and methanol in the ratio of 10:1 (200 mL, ×2), and with an under layer of a solution of chloroform, methanol and water in the ratio of 7:3:1 (200 mL). The combined organic layer was dried over anhydrous sodium sulfate. Then the solvent was removed under reduced pressure. Thus obtained residue was purified by recrystallization from ethanol, dried under reduced pressure to obtain 644 mg (1.535 mmol, 92%) of the title compound as a light pink powder.

Provenance & Evidence