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

HRID 1636647Notes

Reaction equation

HRID 1636647 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:3]=[CH:4][C:5]2[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][C:6]=2[CH:9]=1

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

A mixture of 5-chlorosalicylaldehyde (20.02 g, 0.128 mole) and ethyl 4,4,4-trifluorocrotonate (23.68 g, 0.14 mole) was 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, 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, 3H, 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-cb7029be3d57411bbc513ef716c7a7af
Source dataset
uspto-grants-2000_03
Patent number
US06034256

Reaction notes

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