Water → Ethyl 7-chloro-2H-chromene-3-carboxylate

HRID 902875Notes

Reaction equation

HRID 902875 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+].C(OP([C:21](=[CH2:27])[C:22]([O:24][CH2:25][CH3:26])=[O:23])(OCC)=O)C.O>O1CCCC1.C(OCC)C>[Cl:1][C:2]1[CH:3]=[C:4]2[C:5]([CH:6]=[C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:27][O:10]2)=[CH:8][CH:9]=1

Participants

7

Reactant 4

HCID 962WaterHCID 24758Sodium hydrideHCID 5201014-Chloro-2-hydroxybenzaldehydeHCID 11085761ethyl 2-diethylphosphonoacrylate

Product 1

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

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

4-Chloro-2-hydroxybenzaldehyde (Acta. Chem. Scand., Vol. 53, p. 258, 1999) (510 mg) was dissolved in tetrahydrofuran (40 ml), sodium hydride (60% in oil, 157 mg) was added, and the mixture was stirred at room temperature for 2 hours. A tetrahydrofuran solution (10 ml) of ethyl 2-diethylphosphonoacrylate (J. Org. Chem., Vol. 43, P. 1256, 1978) (769 mg) was added to the reaction mixture, and the resultant mixture was stirred at room temperature for 2 hours and then heated overnight under reflux. After the reaction mixture was cooled to room temperature, water and diethyl ether were added to conduct liquid separation. After the resultant organic layer was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography on silica gel (hexane:ethyl acetate=10:1) to obtain the title compound (247 mg).

Workup

  1. temperatureheated overnight
  2. temperatureunder reflux
  3. temperatureAfter the reaction mixture was cooled to room temperature
  4. customliquid separation
  5. dry with materialAfter the resultant organic layer was dried over anhydrous sodium sulfate
  6. distillationthe solvent was distilled off under reduced pressure
  7. customthe residue was purified by column chromatography on silica gel (hexane:ethyl acetate=10:1)

Sources & evidence

ORD record
ord-4356dc84508d45c894a0e08432a4a7ad
Source dataset
uspto-grants-2008_04
Patent number
US07365205B2

Reaction notes

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