Imidazole → 3-(tert-Butyldimethylsilanyloxy)pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester
Reaction equation
[CH3:1][O:2][C:3]([CH:5]1[CH:9]([OH:10])[CH2:8][CH2:7][N:6]1[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])=[O:4].N1C=CN=C1.[Si:23](Cl)([C:26]([CH3:29])([CH3:28])[CH3:27])([CH3:25])[CH3:24]>C(Cl)Cl.Cl>[CH3:1][O:2][C:3]([CH:5]1[CH:9]([O:10][Si:23]([C:26]([CH3:29])([CH3:28])[CH3:27])([CH3:25])[CH3:24])[CH2:8][CH2:7][N:6]1[C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])=[O:4]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 0 °C
Procedure
A solution containing 3-hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (61, 14.8 g, 60 mmol) in DCM (150 mL) was cooled to 0° C. To this solution was added imidazole (5.4 g, 79 mmol) followed by t-butyl-dimethylsilyl-chloride (10 g, 66 mmol) in two portions. The reaction mixture was warmed to ambient temperature over 1 h. After 5 h, the reaction mixture was diluted with 1M HCl and extracted twice with DCM. The combined organic extracts were dried over anhydrous Na2SO4, filtered, and concentrated to afford 21.2 g (99%) of 3-(tert-butyldimethylsilanyloxy)pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (62) as a yellow oil. 1H NMR (CDCl3, 300 MHz): δ4.38-4.34 (m, 1H), 4.18 (br s, rotomers, 0.5H), 4.04 (app d, J=2.1 Hz, rotomers, 0.5H), 3.74 (s, 3H), 3.62-3.50 (m, 2H), 2.04-1.96 (m, 1H), 1.85-1.78 (m, 1H), 1.46 (s, minor rotomer), 1.41 (s, 9H), 0.92 (s, minor rotomer), 0.86 (s, 9H), 0.11 (s, 6H), 0.09 (s, minor rotomer) ppm.
Workup
- temperatureThe reaction mixture was warmed to ambient temperature over 1 h
- extractionextracted twice with DCM
- dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
- filtrationfiltered
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-b88858c33ddd4f8385adcf4ad56047bf
- Source dataset
- uspto-grants-2013_04
- Patent number
- US08415486B2
Reaction notes
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