Pyridine → methanesulfonic acid (2S,3S)-3-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)-2-hydroxy-4-phenylbutyl ester

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Reaction Steps

A solution of 0.51 g of an 83:17 mixture of the (1S,2S) and (1S,2R) isomers of 2-(1-benzyl-2,3-dihydroxypropyl)-2,3-dihydro-1H-isoindole-1,3-dione, 0.4 ml of pyridine and 1 ml of ethyl acetate is treated with 0.15 ml of methanesulfonyl chloride and the mixture is stirred at room temperature for 4 hours. The mixture is diluted with ethyl acetate and washed with 2% hydrochloric acid, and the extracts are dried and filtered. The filtrate is evaporated and the residue is purified on silica gel with methylene chloride/isopropanol (100:1). After evaporation and drying there is obtained 0.28 g (43%) of pure methanesulfonic acid (2S,3S)-3-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)-2-hydroxy-4-phenylbutyl ester, NMR (CDCl3): 7.7 (m,4H); 7.1 (m,5H); 4.6 (m,2H); 4.3 (m,2H); 3.55 (d,J=7,1H); 3.3 (m,2H); 3.1 (s,3H).

Provenance & Evidence