Conversion of Esters to 2-Acetoxy Esters via 2-Nosyloxy Esters
摘要:
Reaction of 2-nosyloxy esters, available in high yields from the reaction of trimethylsilyl ketene acetals with p-((nitrobenzene)sulfonyl) peroxide, with sodium acetate in DMF produces 2-acetoxy ester in good yields.
The preparation of 2-hydrazinyl esters in high optical purity from 2-sulfonyloxy esters
作者:Robert V Hoffman、Kim Hwa-Ok
DOI:10.1016/s0040-4039(00)88996-0
日期:——
chiral 2-hydroxy esters, react enantiospecifically wilh BocNHNH2 to produce optically pure 2-hydrazinyl ester derivatives in high yields. The reaction of 2-nosyloxy esters with BocNHNH2 gives 2-(Bochydrazinyl) esters, thus providing an efficient (albeit slow) method for the conversion of esters to 2-hydrazinyl ester derivatives.
The present invention provides a compound of a formula (I): wherein the variables are defined herein; to a process for preparing such a compound; and to the use of such a compound in the treatment of a chemokine (such as CCR3) mediated disease state.
The present invention provides a compound of a formula (I):
wherein the variables are defined herein; to a process for preparing such a compound; and to the use of such a compound in the treatment of a chemokine (such as CCR3) mediated disease state.
The present invention provides the compound (S)-4-[4-(3,4-dichloro-2-methyl-phenoxy)-piperidin-1-ylmethyl]-piperidin-1-yl}-3-(4-ftuoro-phenyl)-propionic acid, or a pharmaceutically acceptable salt thereof; to composition comprising such a compound; and to the use of such a compound in the treatment of a chemokine (such as CCR3) mediated disease state (such as asthma or rhinitis).