Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → 8-BROMO-2H-1-BENZOPYRAN-2-ONE

HRID 2233329Notes

Reaction equation

HRID 2233329 reaction equation
[Br:1][C:2]1[C:3]([OH:10])=[C:4]([CH:7]=[CH:8][CH:9]=1)[CH:5]=O.[C:11]([CH:16]=P(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)(OCC)=[O:12]>CN1C(=O)CCC1>[Br:1][C:2]1[CH:9]=[CH:8][CH:7]=[C:4]2[C:3]=1[O:10][C:11](=[O:12])[CH:16]=[CH:5]2

Participants

4

Reactant 2

HCID 70670Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl esterHCID 109105553-Bromo-2-hydroxybenzaldehyde

Product 1

HCID 111604508-BROMO-2H-1-BENZOPYRAN-2-ONEYield 26%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent

Conditions

Temperature
210 °C

Procedure

To a solution of 3-bromo-2-hydroxybenzaldehyde (402 mg, 2.0 mmol) in NMP (5 mL) was added carbethoxymethylene triphenylphosphorane (765 mg, 2.2 mmol). The reaction was heated at 210° C. for 3 h, then was cooled to RT and partitioned between water and ethyl acetate. The layers were separated and the organic layer was dried over MgSO4. Purification by flash chromatography on silica gel (2:1 hexanes/ethyl acetate) yielded the title compound (116 mg, 26%) as a light beige solid: MS (ES) m/e 227.0 (M+H)+.

Workup

  1. temperaturewas cooled to RT
  2. custompartitioned between water and ethyl acetate
  3. customThe layers were separated
  4. dry with materialthe organic layer was dried over MgSO4
  5. customPurification by flash chromatography on silica gel (2:1 hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-d607ff8c56fa4e09962f13c3db57f777
Source dataset
uspto-grants-2010_05
Patent number
US07709496B2

Reaction notes

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