Thiophene → HCID 57053197, compound

HRID 399915Notes

Reaction equation

HRID 399915 reaction equation
O=[C:2]1[C:7]2=[CH:8][CH:9]=[C:10]3[C:14]([CH3:15])=[C:13]([CH3:16])[O:12][C:11]3=[C:6]2[O:5][C:4]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:3]1.S1C=CC=C1.[H][H]>CO.[Pd]>[CH3:16][C:13]1[O:12][C:11]2=[C:6]3[O:5][CH:4]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:3][CH2:2][C:7]3=[CH:8][CH:9]=[C:10]2[C:14]=1[CH3:15]

Participants

6

Reactant 3

HCID 8030ThiopheneHCID 18694146HCID 18694146, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 57053197HCID 57053197, compoundYield 72.9%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalyst2×HCID 887MethanolSolvent

Procedure

A solution of ethyl 6-oxo-2,3-dimethyl-6H-furo[3,2-h][1]benzopyran-8-carboxylate (0.1 mol) in methanol (250 ml) was hydrogenated for 10 hours at 170° C. (pressurized) with palladium on activated carbon, palladium content 5% (2 g) as a catalyst in the presence of a 4% thiophene solution (10 ml). After uptake of hydrogen (3 equiv), the catalyst was filtered off and the filtrate was evaporated. The residue was purified by flash column chromatography over silica gel (eluent: CH2Cl2). The desired fractions were collected and the solvent was evaporated, yielding 20 g (72.9%) of (±)-ethyl 7,8-dihydro-2,3-dimethyl-6H-furo[3,2-h][1]benzopyran-8-carboxylate (interm. 16-a).

Workup

  1. customthe filtrate was evaporated
  2. customThe residue was purified by flash column chromatography over silica gel (eluent: CH2Cl2)
  3. customThe desired fractions were collected
  4. customthe solvent was evaporated

Sources & evidence

ORD record
ord-b52b61fc352e48d3b12640e78fd242b7
Source dataset
uspto-grants-1998_10
Patent number
US05824682

Reaction notes

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