Imidazole → 1-(tert-Butyl) 2-methyl (2R,4R)-4-((tert-butyldimethylsilyl)oxy)pyrrolidine-1,2-dicarboxylate

HRID 908448Notes

Reaction equation

HRID 908448 reaction equation
[Si:1](Cl)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[OH:9][C@H:10]1[CH2:14][N:13]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[C@@H:12]([C:22]([O:24][CH3:25])=[O:23])[CH2:11]1.N1C=CN=C1>CN(C=O)C>[C:4]([Si:1]([CH3:3])([CH3:2])[O:9][C@H:10]1[CH2:14][N:13]([C:15]([O:17][C:18]([CH3:19])([CH3:20])[CH3:21])=[O:16])[C@@H:12]([C:22]([O:24][CH3:25])=[O:23])[CH2:11]1)([CH3:7])([CH3:6])[CH3:5]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 6951202(2R,4R)-4-Hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

Product 1

HCID 141170031-(tert-Butyl) 2-methyl (2R,4R)-4-((tert-butyldimethylsilyl)oxy)pyrrolidine-1,2-dicarboxylateYield 51.1%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
20 °C

Procedure

Tert-Butyldimethylsilylchloride (9.36 g) was added to a mixture of O1-tert-butyl O2-methyl (2R,4R)-4-hydroxypyrrolidine-1,2-dicarboxylate (13.83 g) and imidazole (9.61 g) in DMF (100 ml). The reaction was stirred at 20° C. for 19 hours and then evaporated to dryness. The residues were slurried in diethyl ether and filtered. The filtrate was evaporated to dryness and the residues purified by flash chromatography on silica eluting with increasingly polar mixtures of methanol/dichloromethane (0/100-5/95). Fractions containing the desired product were combined and evaporated to dryness to give O1-tert-butyl O2-methyl (2R,4R) 4-(tert-butyl-dimethyl-silyl)oxypyrrolidine-1,2-dicarboxylate (10.35 g) as a colourless oil. NMR Spectrum: (DMSOd6) 0.00 (6H, s); 0.80 (9H, s); 1.32-1.38 (9H, m); 1.84-1.89 (1H, m); 2.30-2.35 (1H, m); 3.06-3.10 (1H, m); 3.49 (1H, q); 3.59 (3H, d); 4.22-4.26 (1H, m); 4.37 (1H, d).

Workup

  1. customevaporated to dryness
  2. filtrationfiltered
  3. customThe filtrate was evaporated to dryness
  4. customthe residues purified by flash chromatography on silica eluting
  5. temperaturewith increasingly polar mixtures of methanol/dichloromethane (0/100-5/95)
  6. additionFractions containing the desired product
  7. customevaporated to dryness

Sources & evidence

ORD record
ord-b983c52ee7f1441f99f8184f294ddef7
Source dataset
uspto-grants-2011_09
Patent number
US08017611B2

Reaction notes

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