HCID 4736910, compound → 3,4-Dihydro-2H-naphtho[1,2-b]pyran-2-carboxylic acid

HRID 1906888Notes

Reaction equation

HRID 1906888 reaction equation
O=[C:2]1[CH:7]=[C:6]([C:8]([OH:10])=[O:9])[O:5][C:4]2[C:11]3[C:16]([CH:17]=[CH:18][C:3]1=2)=[CH:15][CH:14]=[CH:13][CH:12]=3.[H][H]>[Pd].COCCO>[O:5]1[CH:6]([C:8]([OH:10])=[O:9])[CH2:7][CH2:2][C:3]2[CH:18]=[CH:17][C:16]3[C:11]([C:4]1=2)=[CH:12][CH:13]=[CH:14][CH:15]=3

Participants

5

Reactant 2

HCID 4736910HCID 4736910, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 202110393,4-Dihydro-2H-naphtho[1,2-b]pyran-2-carboxylic acidYield 61.4%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 80192-MethoxyethanolSolvent

Procedure

A mixture of 12 parts of 4-oxo-4H-naphtho[1,2-b]pyran-2-carboxylic acid and 100 parts of 2-methoxyethanol was hydrogenated at normal pressure and at room temperature with 2 parts of palladium-on-charcoal catalyst 10%. After the calculated amount of hydrogen was taken up, the catalyst was filtered off and the filtrate was evaporated, yielding 7 parts (61.4%) of 3,4-dihydro-2H-naphtho[1,2-b]pyran-2-carboxylic acid as a residue (intermediate 19).

Workup

  1. filtrationthe catalyst was filtered off
  2. customthe filtrate was evaporated

Sources & evidence

ORD record
ord-ad19606d2603450bbc79bb6f51765519
Source dataset
uspto-grants-1987_03
Patent number
US04654362

Reaction notes

Loading…