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 produced in Reference Example 29 (870 mg, 1.676 mmol) was dissolved in concentrated hydrochloric acid (10 mL) in an ice bath, and the mixture was stirred at room temperature for 20 minutes and washed chloroform (20 mL×5). Saturated aqueous solution of sodium hydroxide was added to the aqueous layer in an ice bath to adjust the pH to 12.0, and the pH was further adjusted to 7.4 by adding hydrochloric acid. The solution was extracted with a mixed solution (chloroform:methanol, 10:1) (200 mL×2), and then, with lower layer of a mixed solution (200 mL) (chloroform:methanol:water, 7:3:1). The organic layers were combined and dried with anhydrous sodium sulfate, and the solvent was removed by distillation. The residue was purified by recrystallization from ethanol, and the crystals were dried under reduced pressure to obtain 644 mg (1.535 mmol, 92%) of the title compound as a pale pink powder.

Provenance & Evidence