Imidazole → HCID 21186613, compound

HRID 1384322Notes

Reaction equation

HRID 1384322 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 δ7.64 (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-c1d06f99d4c24857a378b055fabe7b32
Source dataset
uspto-grants-2001_07
Patent number
US06258827B1

Reaction notes

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