Benzyl Bromide → 6-Fluoro-7-benzyloxychroman-4-one

HRID 1003624Notes

Reaction equation

HRID 1003624 reaction equation
[F: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].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[O:12][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[O:8][CH2:7][CH2:6][C:5]2=[O:13]

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 211866006-fluoro-7-hydroxy-3,4-dihydro-2H-1-benzopyran-4-one

Product 1

HCID 211865906-Fluoro-7-benzyloxychroman-4-oneYield 73%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A mixture of 6-fluoro-7-hydroxychroman-4-one (the compound of Preparation 29, 0.93 g, 5.11 mmol), benzyl bromide (0.61 mL, 5.13 mmol), potassium carbonate (1.41 g, 10.2 mmol) in acetone (100 mL) was stirred at ambient temperature overnight. The mixture was cooled, filtered, and concentrated to a yellow solid. This residue was recrystallized from ethyl acetate/ether to give 1.02 g (73%) of 6-fluoro-7-benzyloxychroman-4-one in two crops as cream white crystals which had: mp 155-156° C.; NMR δ 7.58 (d, J=11 Hz, 1 H), 7.46-7.33 (m, 5 H), 6.54 (d, J=6.7 Hz, 1 H), 5.16 (d, 2 H), 4.50 (t, J=6.4 Hz, 2 H), 2.75 (t, J=6.4 Hz, 2 H). Analysis calculated for C16H13FO2 : C, 70.58; H, 4.81. Found: C, 70.45; H, 4.80.

Workup

  1. temperatureThe mixture was cooled
  2. filtrationfiltered
  3. concentrationconcentrated to a yellow solid
  4. customThis residue was recrystallized from ethyl acetate/ether

Sources & evidence

ORD record
ord-4e3bfe26b5ce41ff92bb2952fe87a9e1
Source dataset
uspto-grants-2000_04
Patent number
US06046213

Reaction notes

Loading…