Potassium Carbonate → ethyl 6-chloro-2-(trifluoromethyl)-2H-chromene-3-carboxylate

HRID 854936Notes

Reaction equation

HRID 854936 reaction equation
[Cl:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.[F:11][C:12]([F:21])([F:20])/[CH:13]=[CH:14]/[C:15]([O:17][CH2:18][CH3:19])=[O:16].C([O-])([O-])=O.[K+].[K+]>CN(C=O)C.O>[Cl:1][C:2]1[CH:9]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:10][CH:13]([C:12]([F:11])([F:21])[F:20])[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:7]2

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 124815-Chloro-salicylaldehydeHCID 5371261Ethyl (2E)-4,4,4-trifluoro-2-butenoate

Product 1

HCID 15458898ethyl 6-chloro-2-(trifluoromethyl)-2H-chromene-3-carboxylateYield 138.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

5-Chlorosalicylaldehyde (20.02 g, 0.128 mole) and ethyl 4,4,4-trifluorocrotonate (23.68 g, 0.14 mole) were dissolved in anhydrous DMF, warmed to 60° C. and treated with anhydrous K2CO3 (17.75 g, 0.128 mole). The solution was maintained at 60° C. for 20 hours, cooled to room temperature, and diluted with water. The solution was extracted with ethyl acetate. The combined extracts were washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo to afford 54.32 g of an oil. The oil was dissolved in 250 mL of methanol and 100 mL of water, whereupon a white solid formed that was isolated by filtration. The resulting solid was washed with water and dried in vacuo, to afford the ester as a yellow solid (24.31 g, 62%): mp 62-64° C. 1H NMR (CDCl3/90 MHz) 7.64 (s, 1H), 7.30-7.21 (m, 2H), 6.96 (d, 1H, J=Hz), 5.70 (q, 1H, J=Hz), 4.30 (q, 2H, J=7.2 Hz), 1.35 (t, 31H, J=7.2 Hz).

Workup

  1. temperatureThe solution was maintained at 60° C. for 20 hours
  2. temperaturecooled to room temperature
  3. extractionThe solution was extracted with ethyl acetate
  4. washThe combined extracts were washed with brine
  5. dry with materialdried over anhydrous MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-ccfd25e7525e459b9c382632a7136bd8
Source dataset
uspto-grants-2007_08
Patent number
US07259266B2

Reaction notes

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