| 摘要 |
One-pot process for preparing N-alkoxycarbonyl-protected esters (I)-(III) comprises reacting N-acyl-protected esters (IV) or N-benzoyl-protected esters (V) or (VI) with a dicarbonate ester (VII) in a dry organic solvent at -50 to +50 deg C in the presence of a base, cooling the reaction mixture, adding methanol and hydrazine, and purifying the reaction mixture. One-pot process for preparing N-alkoxycarbonyl-protected esters of formula (I)-(III) comprises reacting N-acyl-protected esters of formula (IV) or N-benzoyl-protected esters of formula (V) or (VI) with a dicarbonate ester of formula (VII) in a dry organic solvent at -50 to +50 deg C in the presence of a base, cooling the reaction mixture, adding methanol and hydrazine, and purifying the reaction mixture. R<1> = H, optionally substituted alkyl, optionally substituted aryl, heteroaryl, cycloalkyl, alkoxy, alkylamino, aryloxy or arylamino; R<2> = methyl, substituted alkyl, optionally substituted aryl or cycloalkyl; R<3> = OR<2>, optionally substituted alkyl, optionally substituted aryl, heteroaryl or cycloalkyl; R<4> = optionally substituted alkyl or optionally substituted aryl; R<5> = H, methyl or phenyl.
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