Sodium hydride → Ethyl 7-chloro-2H-chromene-3-carboxylate

HRID 2104402Notes

Reaction equation

HRID 2104402 reaction equation
[Cl:1][C:2]1[CH:9]=[CH:8][C:5]([CH:6]=O)=[C:4]([OH:10])[CH:3]=1.[H-].[Na+].[CH2:13]([O:15][C:16](=[O:27])[C:17](P(OCC)(OCC)=O)=[CH2:18])[CH3:14]>O1CCCC1>[CH2:13]([O:15][C:16]([C:17]1[CH2:18][O:10][C:4]2[C:5]([CH:6]=1)=[CH:8][CH:9]=[C:2]([Cl:1])[CH:3]=2)=[O:27])[CH3:14]

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 5201014-Chloro-2-hydroxybenzaldehydeHCID 11085761ethyl 2-diethylphosphonoacrylate

Product 1

HCID 22934791Ethyl 7-chloro-2H-chromene-3-carboxylateYield 31.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

4-Chloro-2-hydroxybenzaldehyde (Acta. Chem. Scand., vol. 53, p. 258 (1999)) (510 mg) was dissolved in tetrahydrofuran (40 mL), and sodium hydride (60% in oil, 157 mg) was added thereto, followed by stirring at room temperature for 2 hours. To the reaction mixture was added a solution of 2-diethylphosphonoacrylic acid ethyl ester (J. Org. Chem., vol. 43, p. 1256 (1978)) (769 mg) in tetrahydrofuran (10 mL), and the thus-obtained mixture was stirred at room temperature for 2 hours, followed by heating under reflux overnight. After the reaction mixture was cooled to room temperature, the mixture was partitioned between water and diethyl ether. The organic layer was dried over sodium sulfate anhydrate, and the solvent was distilled away under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1), to thereby give the title compound (247 mg).

Workup

  1. stirringthe thus-obtained mixture was stirred at room temperature for 2 hours
  2. temperatureby heating
  3. temperatureunder reflux overnight
  4. temperatureAfter the reaction mixture was cooled to room temperature
  5. customthe mixture was partitioned between water and diethyl ether
  6. dry with materialThe organic layer was dried over sodium sulfate anhydrate
  7. distillationthe solvent was distilled away under reduced pressure
  8. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1)

Sources & evidence

ORD record
ord-51ebb8498933459f850000de9e110bc1
Source dataset
uspto-grants-2009_08
Patent number
US07576135B2

Reaction notes

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