Imidazole → HCID 15434308, compound

HRID 1810597Notes

Reaction equation

HRID 1810597 reaction equation
[CH3:1][O:2][C:3]([C:5]1([CH3:19])[CH2:14][CH2:13][C:12]2[C:7](=[C:8]([CH3:18])[C:9]([CH3:17])=[C:10]([OH:16])[C:11]=2[CH3:15])[O:6]1)=[O:4].[C:20]([Si:24]([CH3:28])([CH3:27])OCl)([CH3:23])([CH3:22])[CH3:21].N1C=CN=C1>CN(C=O)C.C(OCC)(=O)C>[CH3:1][O:2][C:3]([C:5]1([CH3:19])[CH2:14][CH2:13][C:12]2[C:7](=[C:8]([CH3:18])[C:9]([CH3:17])=[C:10]([O:16][Si:24]([C:20]([CH3:23])([CH3:22])[CH3:21])([CH3:28])[CH3:27])[C:11]=2[CH3:15])[O:6]1)=[O:4]

Participants

6

Reactant 3

HCID 795ImidazoleHCID 10171518HCID 10171518, compoundHCID 19793901HCID 19793901, compound

Product 1

HCID 15434308HCID 15434308, compoundYield 99%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

Step a. A solution of 6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic acid methyl ester (i, 41.9 mmol), t-butyl-dimethyl-silyloxy chloride (62.8 mmol), and imidazole (172.2 mmol) in 100 mL of DMF was stirred at 85-95° C. for 16 h, and cooled to room temperature. The solution was diluted with 200 mL of ethyl acetate, washed, in tandem, with H2O, 1% HCl, saturated NaHCO3, and brine, dried with Na2SO4, and concentrated. Purification by flash silica gel chromatography gave the product, 6-(t-butyl-dimethyl-silyloxy)-2,5,7,8-tetramethyl-chroman-2-carboxylic acid methyl ester (ii), as white solid in 99% yield. 1H NMR (300 MHz, CDCl3) δ 0.11 (s, 6H), 1.04 (s, 9H), 1.62 (s, 3H), 1.86-1.76 (m, 1H), 2.01 (s, 3H), 2.11 (s, 3H), 2.16 (s, 3H), 2.22-2.30 (m, 1H), 3.49-3.65 (m, 2H), 3.69 (s, 3H), 4.22 (s, 1H).

Workup

  1. washwashed, in tandem, with H2O, 1% HCl, saturated NaHCO3, and brine
  2. dry with materialdried with Na2SO4
  3. concentrationconcentrated
  4. customPurification by flash silica gel chromatography

Sources & evidence

ORD record
ord-28dbceed09364bc292a343e16a884acd
Source dataset
uspto-grants-2013_01
Patent number
US08362071B2

Reaction notes

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