(2S,4R)-4-Hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester → 1-(1,1-Dimethylethyl) 2-methyl (2S,4R)-4-(((4-bromo-1,3-dihydro-2H-isoindol-2-yl)carbonyl)oxy)-1,2-pyrrolidinedicarboxylate
Reaction equation
[OH:1][C@H:2]1[CH2:6][N:5]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[C@H:4]([C:14]([O:16][CH3:17])=[O:15])[CH2:3]1.[C:18](C1NC=CN=1)(C1NC=CN=1)=[O:19].[Br:30][C:31]1[C:32]2[C:36]([CH:37]=[CH:38][CH:39]=1)=[CH:35][NH:34][CH:33]=2>CN(C)C(=O)C>[Br:30][C:31]1[CH:39]=[CH:38][CH:37]=[C:36]2[C:32]=1[CH2:33][N:34]([C:18]([O:1][C@H:2]1[CH2:6][N:5]([C:7]([O:9][C:10]([CH3:11])([CH3:12])[CH3:13])=[O:8])[C@H:4]([C:14]([O:16][CH3:17])=[O:15])[CH2:3]1)=[O:19])[CH2:35]2Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 60 °C
Procedure
To a solution containing 0.5 g of (2S,4R)-1-tert-butyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate (2 mmol) in 5 mL of N,N-dimethylacetamide, was added 370 mg of carbonyl diimidazole (1.1 equiv.). The reaction was heated at 60° C. for 1 hr, then 400 mg of 4-bromoisoindole (2 mmol) was added. The reaction was continued at 60° C. overnight. After cooling down, the reaction mixture was extracted with 50 mL of EtOAc, and washed with water, brine, and dried over Na2SO4. After filtration and concentration, the residue was purified by flash column chromatography on silica gel using heptanes/EtOAc (v/v 5/2), giving white solid 745 mg (79%). LC-MS: m/z=369.2 (ES+, M+1-Boc).
Workup
- temperatureAfter cooling down
- extractionthe reaction mixture was extracted with 50 mL of EtOAc
- washwashed with water, brine
- dry with materialdried over Na2SO4
- filtrationAfter filtration and concentration
- customthe residue was purified by flash column chromatography on silica gel
Sources & evidence
- ORD record
- ord-f5cbdbc5c43143789c91775b9e44d874
- Source dataset
- uspto-grants-2014_06
- Patent number
- US08741837B2
Reaction notes
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