Hydrochloric Acid → ethyl 7-(1,1-Dimethylethyl)-2-(pentafluoroethyl)-2H-1-benzopyran-3-carboxylate

HRID 722321Notes

Reaction equation

HRID 722321 reaction equation
[C:1]([C:5]1[CH:6]=[C:7]([OH:13])[C:8](=[CH:11][CH:12]=1)[CH:9]=O)([CH3:4])([CH3:3])[CH3:2].[F:14][C:15]([F:27])([C:23]([F:26])([F:25])[F:24])[CH:16]=[CH:17][C:18]([O:20][CH2:21][CH3:22])=[O:19].C([O-])([O-])=O.[K+].[K+].Cl>CN(C=O)C.C(OCC)(=O)C>[CH3:2][C:1]([C:5]1[CH:12]=[CH:11][C:8]2[CH:9]=[C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:16]([C:15]([F:14])([F:27])[C:23]([F:25])([F:24])[F:26])[O:13][C:7]=2[CH:6]=1)([CH3:4])[CH3:3]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 11430Potassium CarbonateHCID 11347794Ethyl 4,4,5,5,5-pentafluoro-2-pentenoateHCID 137652724-tert-Butyl-2-hydroxybenzaldehyde

Product 1

HCID 21883731ethyl 7-(1,1-Dimethylethyl)-2-(pentafluoroethyl)-2H-1-benzopyran-3-carboxylateYield 70%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of 4-tert-butylsalicylaldehyde Example 8, step 1 (1.15 g, 6.4 mm) and the ethyl ester from Step 2 (1.59 g, 7.3 mmol) was dissolved in anhydrous DMF (4 mL). With stirring, K2CO3 (1.10 g, 9.0 mmol) was added causing the reaction to become deep red. The reaction was stirred at room temperature for 100 hours, acidified with 3 N HCl, diluted with ethyl acetate and washed with saturated NaHCO3 solution, brine, dried over MgSO4, filtered and concentrated in vacuo yielding a brown oil. This oil was purified by flash chromatography over silica gel, eluting with 10% ethyl acetate/hexanes to afford a yellow oil (1.72 g, 70%): 1H NMR (CDCl3/300 MHz) 7.76 (s, 1H), 7.14 (d, 1H, J=8.1 Hz), 7.04 (dd, 1H, J=8.1 Hz 1.8 Hz), 6.94 (s, 1H), 5.92 (dd, 1H, J=22.4 Hz 3.0 Hz), 4.32 (m, 2H), 1.35 (t, 3H, J=7.2 Hz), 1.30 (s, 9H).

Workup

  1. customthe reaction
  2. stirringThe reaction was stirred at room temperature for 100 hours
  3. washwashed with saturated NaHCO3 solution, brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customyielding a brown oil
  8. customThis oil was purified by flash chromatography over silica gel
  9. washeluting with 10% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-05a04174962149dbac54aea1729b51c7
Source dataset
uspto-grants-2006_11
Patent number
US07138411B2

Reaction notes

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