(2S,4S)-4-{[2-(5-Ethyl-1-methyl-7-oxo-3-propyl-1,7-dihydro-pyrazolo[4,3-d]pyrimidin-6-yl)-acetyl]-heptyl-amino}-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester 在
sodium carbonate 作用下,
以
甲醇 、
水 为溶剂,
以79%的产率得到(2S,4S)-4-{[2-(5-Ethyl-1-methyl-7-oxo-3-propyl-1,7-dihydro-pyrazolo[4,3-d]pyrimidin-6-yl)-acetyl]-heptyl-amino}-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester