Trifluoroacetic acid → 5-(2,3-dihydro-benzo[1,4]dioxin-5-ylmethyl)-1H-imidazole

HRID 747265Notes

Reaction equation

HRID 747265 reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[C:10]([CH:11]([C:13]3[N:14]=[CH:15][N:16](C(C4C=CC=CC=4)(C4C=CC=CC=4)C4C=CC=CC=4)[CH:17]=3)O)[C:5]=2[O:4][CH2:3][CH2:2]1.C(O)(C(F)(F)F)=O.C([SiH](CC)CC)C>ClCCl>[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[C:10]([CH2:11][C:13]3[NH:14][CH:15]=[N:16][CH:17]=3)[C:5]=2[O:4][CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 6422Trifluoroacetic acid2×HCID 12052TriethylsilaneHCID 59749547(2,3-dihydro-benzo[1,4]dioxin-5-yl)-(1-trityl-1H-imidazol-4-yl)-methanol2×

Product 1

HCID 597495595-(2,3-dihydro-benzo[1,4]dioxin-5-ylmethyl)-1H-imidazoleYield 72.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of (2,3-dihydro-benzo[1,4]dioxin-5-yl)-(1-trityl-1H-imidazol-4-yl)-methanol (Intermediate A3) (1 g, 2.11 mmol) in dichloromethane (30 mL) was reacted with TFA:trifluoroacetic acid (5.3 mL, 68 mmol)) and triethylsilane (TES) (2.8 mL, 17 mmol) at rt for 24 h. The mixture was evaporated under reduced pressure and quenched with solid NaHCO3. This material was subjected to an aqueous work-up and the residue was purified by chromatography on silica gel with 5% NH3-MeOH:CH2Cl2 to yield 5-(2,3-dihydro-benzo[1,4]dioxin-5-ylmethyl)-1H-imidazole (Intermediate A4) 330 mg (72%).

Workup

  1. customThe mixture was evaporated under reduced pressure
  2. customquenched with solid NaHCO3
  3. customthe residue was purified by chromatography on silica gel with 5% NH3-MeOH

Sources & evidence

ORD record
ord-548ac83fb7be46dbb12d03f48e7917a4
Source dataset
uspto-grants-2008_07
Patent number
US07396849B2

Reaction notes

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