147118-39-6

147118-38-5

147118-39-6

Under ice bath cooling conditions, 16 g of methyl 7-[4-(4-fluorophenyl)-6-isopropyl-2-(N-methylmethylsulfonamido)-5-pyrimidinyl]-(3R)-tert-butyldimethylsilyloxy-5-oxo-(6E)-heptanoate (compound ii) was dissolved in 100 mL of acetonitrile. Subsequently, a 400 mL solution prepared from 48% hydrogen fluoride and acetonitrile at a volume ratio of 1:19 was slowly added dropwise. The reaction mixture was gradually warmed to room temperature and stirred continuously for 1.5 hours. Upon completion of the reaction, the reaction mixture was neutralized with sodium bicarbonate solution and subsequently extracted with ether. The organic layer was washed with aqueous sodium chloride solution, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. Eventually, the residual ether was removed by distillation to afford 13 g (yield: 100%) of the target product 7-[4-(4-fluorophenyl)-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyrimidin-5-yl]-(3R)-3-hydroxy-5-oxo-(E)-6-heptenoic acid methyl ester (Compound iii) in the form of a syrupy substance.