反应详情

温度

80 °C

Via Mesylate: A biphasic solution of 13.9 ml (215 mmol) methanesulfonic acid, 29.8 ml (215 mmol) triethylamine and 58.7 g (224 mmol) triphenylphosphine in 150 ml toluene was added to a suspension of 60 g (179 mmol) (2S,4R)-4-Hydroxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acid methyl ester in 300 ml toluene which was stirred mechanically. After adding 44.9 ml (233 mmol) of diisopropyl azodicaboxylate (exothermic!) the solution was heated for 2.5 h at 80° C. 300 ml water was added at RT and extracted with ethylacetate (3×300 ml). The organic phase was washed with aqueous 10% KHSO4 (2×100 ml), 10% NaCl (2×150 ml), dried over Na2SO4 and evaporated to give 180 g of crude product. Flash chromatography (ethyl acetate/hexane 1:1) gave 63.7 g (86%) of (4S, 2S)-4-Methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acid methylester.

1. extractionextracted with ethylacetate (3×300 ml)
2. washThe organic phase was washed with aqueous 10% KHSO4 (2×100 ml), 10% NaCl (2×150 ml)
3. dry with materialdried over Na2SO4
4. customevaporated
5. customto give 180 g of crude product