Imidazole → ethyl (R)-alpha-(t-butyldimethylsilyloxy)-alpha-phenylacetate

HRID 1682746Notes

Reaction equation

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

Participants

Conditions

Temperature: 40 °C

Procedure

A solution of 31.4 g of t-butyldimethylsilyl chloride in 200 ml of dimethylformamide was added dropwise to a solution of 25 g of ethyl (R)-(-)-mandelate and 28.4 g of imidazole in 600 ml of anhydrous dimethylformamide, and the resulting mixture was stirred overnight at 40° C. The dimethylformamide solvent was then removed by distillation under reduced pressure, and the residue was mixed with water and then extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate, and the solvent was then removed by distillation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 1:10 by volume mixture of ethyl acetate and hexane as the eluent,. The title compound was obtained as a liquid, boiling at 129° C./3.5 mmHg (466 Pa) by distillation in vacuo. [α]D23 -40.8° (c=1.07, chloroform)

Workup

customThe dimethylformamide solvent was then removed by distillation under reduced pressure
additionthe residue was mixed with water
extractionextracted with ethyl acetate
dry with materialThe extract was dried over anhydrous sodium sulfate
customthe solvent was then removed by distillation under reduced pressure
customThe resulting residue was purified by column chromatography through silica gel
additionby volume mixture of ethyl acetate and hexane as the eluent

Sources & evidence

ORD record: ord-12628d4d7a724f21a01144d5c2b10a54
Source dataset: uspto-grants-1997_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05635534

Reaction notes

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