methyl-(2S)-3-hydroxy-2-({3-[(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin5yl)methyl]phenyl}sulfonamido)propanoate 以40%的产率得到(2S)-3-hydroxy-2-({3-[(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)methyl]phenyl}sulfonamido)propanamide