Ethyl 4-oxo-4H-1-benzopyran-2-carboxylate → Ethyl Chroman-2-carboxylate

A solution of ethyl 4-oxo-4H-1-benzopyran-2-carboxylate (2.0 g, 9.17 mmol) in methanol (60 ml), chloroform (25 ml) and glacial acetic acid (20 ml) was added with 10% palladium-on-charcoal and the mixture was left under stirring at room pressure and temperature for 24 h. under hydrogen atmosphere. After that, the catalyst was filtered off and the filtrate was evaporated to dryness. The residue was redissolved in ethyl ether and washed successively with a 5% sodium bicarbonate solution and a sodium chloride saturated solution. The mixture was dried and the solvent was evaporated off under reduced pressure, to obtain 1.575 g of the title product (84% yield).

1. waitthe mixture was left
2. filtrationAfter that, the catalyst was filtered off
3. customthe filtrate was evaporated to dryness
4. dissolutionThe residue was redissolved in ethyl ether
5. washwashed successively with a 5% sodium bicarbonate solution
6. customThe mixture was dried
7. customthe solvent was evaporated off under reduced pressure

ORD-Eintrag

ord-0493502a233544249da36db96ee3a3b0

Quelldatensatz

uspto-grants-1999_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05990142