Chromocarb → 3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

HRID 1752277Notes

Reaction equation

HRID 1752277 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=O)[CH:3]=[C:2]1[C:12]([OH:14])=[O:13].[H][H]>CO.O.[Pd]>[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][CH:2]1[C:12]([OH:14])=[O:13]

Participants

6

Reactant 2

HCID 2741ChromocarbHCID 178418361HCID 178418361, compound

Product 1

HCID 27236653,4-dihydro-2H-1-benzopyran-2-carboxylic acidYield 95%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a suspension of commercially available chromone-2-carboxylic acid (50 g, 281 mmol) in methanol (500 mL), slurry of (10% Pd/C wet, 5 g) in water (10 mL) was added under nitrogen atmosphere. The mixture was hydrogenated at 60 psi at room temperature (RT) and further maintained hydrogen reservoir up to 60 psi for 2 h. The progress of reaction was monitored by TLC. Reaction mixture was filtered through celite and the filtrate was concentrated under reduced pressure to yield chromane-2-carboxylic acid as off-white solid (44.7 g, 95%). m/z-178.02.

Workup

  1. additionwas added under nitrogen atmosphere
  2. customwas hydrogenated at 60 psi at room temperature
  3. customThe progress of reaction
  4. customReaction mixture
  5. filtrationwas filtered through celite
  6. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-3d9d53aeee584f898cc79c84b49b383a
Source dataset
uspto-grants-2015_10
Patent number
US09163001B2

Reaction notes

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