2H-chromene-3-carboxylic acid → Chroman-3-carboxylic acid

HRID 1447786Notes

Reaction equation

HRID 1447786 reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[CH:4]=[C:3]([C:11]([OH:13])=[O:12])[CH2:2]1>CO.[Pd]>[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[CH2:4][CH:3]([C:11]([OH:13])=[O:12])[CH2:2]1

Participants

4

Reactant 1

HCID 3223042H-chromene-3-carboxylic acid

Product 1

HCID 2795458Chroman-3-carboxylic acid

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

A solution of 10.4 g of the methyl ester of 2H-1-benzopyran-3-carboxylic acid (Taylor et al., supra) in 50 ml of methanol containing 300 mg of 10% palladium-on-carbon catalyst was hydrogenated in a Parr apparatus for 1.5 hours, at an initial pressure of 44 psig. The mixture then was filtered through a Celite pad, the filtrate was stripped of solvent, and the product was vacuum distilled to give the methyl ester of 3,4-dihydro-2H-1-benzopyran-3-carboxylic acid (2A), as a colorless liquid, bp: 86°-88° C. (0.01 Torr.).

Workup

  1. filtrationThe mixture then was filtered through a Celite pad
  2. distillationdistilled

Sources & evidence

ORD record
ord-766a49bae00947be9104a00929d887d6
Source dataset
uspto-grants-1979_12
Patent number
US04178380

Reaction notes

Loading…