Iodoethane → 6,8-Difluoro-7-ethoxy-4-methylcoumarin

HRID 355403Notes

Reaction equation

HRID 355403 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[C:10]([F:13])[C:11]=1[OH:12])[O:8][C:7](=[O:14])[CH:6]=[C:5]2[CH3:15].[CH2:16](I)[CH3:17].C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[C:10]([F:13])[C:11]=1[O:12][CH2:16][CH3:17])[O:8][C:7](=[O:14])[CH:6]=[C:5]2[CH3:15]

Participants

5

Reactant 3

HCID 6340Iodoethane2×HCID 11430Potassium CarbonateHCID 10176707Marina Blue

Product 1

HCID 27626436,8-Difluoro-7-ethoxy-4-methylcoumarinYield 44.3%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A solution of Compound 5 (0.10 g, 0.47 mmol) and ethyl iodide (112 μL, 1.4 mmol) in acetone (10 mL) is stirred at reflux with potassium carbonate (207 mg, 1.5 mmol) for 72 hours, during which additional ethyl iodide (2×200 μL) is added at 24 and 48 hours. After cooling, the reaction mixture is filtered and the filtrate is concentrated to a colorless solid. This solid is purified by preparative TLC (silica gel, 1000 μm plate, eluting with ethyl acetate/hexanes 1:1) to give 50 mg of nonfluorescent Compound 7 as a colorless solid. UV-vis (MeCN): 298 nm, ε=7,770 cm-1M-1 ; 279 nm, ε=11,080 cm-1 M-1. Rf (ethyl acetate/hexanes 3:2) 0.75. 1H NMR (CDCl3) 7.10 (dd, 1H), 6.28 (s, 1H), 4.38 (q, 2H), 2.39 (s, 3H), 1.42 (t, 3H). 19F NMR (CDCl3) 132.2 (t, 1F), 146.9 (d, 1F). Anal. calcd for C12H10O3F2 : C, 60.00; H, 4.20; N, 0.00; Found: C, 59.98; H, 4.27; N, 0.01.

Workup

  1. additionis added at 24 and 48 hours
  2. temperatureAfter cooling
  3. filtrationthe reaction mixture is filtered
  4. concentrationthe filtrate is concentrated to a colorless solid
  5. customThis solid is purified by preparative TLC (silica gel, 1000 μm plate, eluting with ethyl acetate/hexanes 1:1)

Sources & evidence

ORD record
ord-7960fd29e085417792121641bccad6d4
Source dataset
uspto-grants-1998_11
Patent number
US05830912

Reaction notes

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