Methanesulfonic Acid → (4S,2S)-4-Methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acid methylester
Reaction equation
[CH3:1][S:2]([OH:5])(=[O:4])=[O:3].C(N(CC)CC)C.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[CH3:32][O:33][C:34]([C@@H:36]1[CH2:40][C@@H:39](O)[CH2:38][N:37]1[S:42]([C:45]1[CH:54]=[CH:53][C:52]2[C:47](=[CH:48][CH:49]=[CH:50][CH:51]=2)[CH:46]=1)(=[O:44])=[O:43])=[O:35].N(C(OC(C)C)=O)=NC(OC(C)C)=O>C1(C)C=CC=CC=1.CCOC(C)=O.CCCCCC.O>[CH3:32][O:33][C:34]([C@@H:36]1[CH2:40][C@H:39]([O:3][S:2]([CH3:1])(=[O:5])=[O:4])[CH2:38][N:37]1[S:42]([C:45]1[CH:54]=[CH:53][C:52]2[C:47](=[CH:48][CH:49]=[CH:50][CH:51]=2)[CH:46]=1)(=[O:44])=[O:43])=[O:35]Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 80 °C
Procedure
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 (EtOAc/hexane 1:1) gave 63.7 g (86%) of (4S,2S)-4-Methanesulfonyloxy-1-(naphthalene-2-sulfonyl)-pyrrolidine-2-carboxylic acid methylester.
Workup
- extractionextracted with ethylacetate (3×300 ml)
- washThe organic phase was washed with aqueous 10% KHSO4 (2×100 ml), 10% NaCl (2×150 ml)
- dry with materialdried over Na2SO4
- customevaporated
- customto give 180 g of crude product
Sources & evidence
- ORD record
- ord-e0c4e6c6aef648f9a133f5bbba99ea7c
- Source dataset
- uspto-grants-2003_04
- Patent number
- US06541638B2
Reaction notes
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