Reaction #832070

Reaction equation

thiobenzoic acid

sodium hydride

(2S,4R)-1-(t-butoxycarbonyl)-2-ethoxycarbonyl -4-(p-toluenesulfonyloxy)pyrrolidine

→

(2S,4S)-1-(t-butoxycarbonyl)-2-ethoxycarbonyl -4-benzoylthiopyrrolidine

Yield 70.5%

Solvents

sodium iodide

dimethylformamide

dimethylformamide

Conditions

Workup

1. 1
   Temperaturecooled on an ice bath, to which
2. 2
   workup.DISSOLUTIONAfter concentration of the reaction mixture, the thus obtained residue was dissolved in
3. 3
   Washbenzene, and the resulting organic layer was washed with 5% sodium bicarbonate aqueous solution, 10% citric acid aqueous solution and water in that order
4. 4
   Dryingby drying over sodium sulfate and subsequent evaporation of the solvent under a reduced pressure
5. 5
   OtherThe resulting residue was purified by a silica gel column chromatography

Procedure

Next, 36.4 g of thiobenzoic acid was dissolved in 300 ml of dimethylformamide and cooled on an ice bath, to which was subsequently added 10.5 g of sodium hydride. To this were added 102 g of (2S,4R)-1-(t-butoxycarbonyl)-2-ethoxycarbonyl -4-(p-toluenesulfonyloxy)pyrrolidine dissolved in 200 ml of dimethylformamide and 37.5 g of sodium iodide, followed by heating at 80° C. for 3 hours. After concentration of the reaction mixture, the thus obtained residue was dissolved in .benzene, and the resulting organic layer was washed with 5% sodium bicarbonate aqueous solution, 10% citric acid aqueous solution and water in that order, followed by drying over sodium sulfate and subsequent evaporation of the solvent under a reduced pressure. The resulting residue was purified by a silica gel column chromatography to yield 66 g of (2S,4S)-1-(t-butoxycarbonyl)-2-ethoxycarbonyl -4-benzoylthiopyrrolidine.

Source