Imidazole → 3-(tert-Butyldimethylsilanyloxy)pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

HRID 1965202Notes

Reaction equation

HRID 1965202 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

6

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

  1. temperatureThe reaction mixture was warmed to ambient temperature over 1 h
  2. extractionextracted twice with DCM
  3. dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-b88858c33ddd4f8385adcf4ad56047bf
Source dataset
uspto-grants-2013_04
Patent number
US08415486B2

Reaction notes

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