Imidazole → HCID 21186613, compound

HRID 1003625Notes

Reaction equation

HRID 1003625 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[OH:12])[O:8][CH2:7][CH2:6][C:5]2=[O:13].N1C=CN=C1.[CH:19]([Si:22](Cl)([CH:26]([CH3:28])[CH3:27])[CH:23]([CH3:25])[CH3:24])([CH3:21])[CH3:20].O>CN(C)C=O>[CH3:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[O:12][Si:22]([CH:26]([CH3:28])[CH3:27])([CH:23]([CH3:25])[CH3:24])[CH:19]([CH3:21])[CH3:20])[O:8][CH2:7][CH2:6][C:5]2=[O:13]

Participants

6

Reactant 4

HCID 795ImidazoleHCID 962WaterHCID 139400Triisopropylsilyl chlorideHCID 21186627HCID 21186627, compound

Product 1

HCID 21186613HCID 21186613, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A mixture of 6-methyl-7-hydroxychroman-4-one (the compound of Preparation 32, 1.50 g, 8.42 mmol), imidazole (1.15 g, 16.9 mmol), and triisopropylsilyl chloride (2.0 mL, 9.2 mmol) in dimethylformamide (30 mL) was stirred overnight at ambient temperature. The reaction was poured into water and extracted with ether (2×). The combined organic layer was washed with 1 N lithium chloride (2×), dried over magnesium sulfate, and concentrated to afford 3.01 g (100%) of 6-methyl-7-triisopropylsilyloxychroman-4-one as a dull yellow oil which had: NMR δ 7.64 (s, 1 H), 6.30 (s, 1 H), 4.45 (t, J=6.4 Hz, 2 H), 2.70 (t, J=6.4 Hz, 2 H), 2.14 (s, 3 H), 1.40-1.25 (m, 3 H), 1.09 (d, J=7.3 Hz, 18 H). The product also had a small silyl impurity and residual dimethylformamide present but was suitable for subsequent reaction.

Workup

  1. extractionextracted with ether (2×)
  2. washThe combined organic layer was washed with 1 N lithium chloride (2×)
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-2dd1587528ff45d99a9d71d25e3110ee
Source dataset
uspto-grants-2000_04
Patent number
US06046213

Reaction notes

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