反应详情

Step 3 contains three sub-steps. In step 3a, the (−)-(2R,3S)-2-Amino-3-hydroxy-3-pyridin-4-yl-1-pyrrolidin-1-yl-propan-1-one di-p-toluoyl-L-tartrate (ON-PYRAMIDE DPTL Tartrate) is treated with aqueous KOH/Ethanol and acetone to give the corresponding free base, i.e., (−)-(2R,3S)-2-Amino-3-hydroxy-3-pyridin-4-yl-1-pyrrolidin-1-yl-propan-1-one (ON-PYRAMID free base). Following this, there is a resin treatment with a sulfonic resin. Finally, tartrate formation takes place by treatment of the free base with L-tartaric acid in the presence of denatured ethanol. The detailed manufacturing process is given below: