ethyl 1-oxo-2,3-dihydro-1H-indene-2-carboxylate → Ethyl 1H-indene-2-carboxylate

2-Carbethoxy-1-indanone was dissolved in dry methanol at room temperature, to which sodium borohydride was added in three lots while the reaction mixture was kept stirring. The reaction mixture was further stirred for 30 minutes, after which the solid was filtered and the filtrate was evaporated to dryness. The residue was dissolved in dry benzene, to which catalytic amount of p-toluenesulfonic acid was added and the reaction mixture was stirred for one hour. The p-toluenesulfonic acid was filtered off and the filtrate was concentrated to yield ethyl indene-2-carboxylate. The ethyl indene-2-carboxylate was dissolved in methanol and 1.0 equivalent of aqueous sodium hydroxide solution was added and the reaction mixture was kept stirring for overnight. The next day, the reaction was terminated by evaporating the methanol, followed by diluting the residue with water, brought to neutral pH and the precipitated indene-2-carboxylic acid was filtered. NMR: (CDCl3):δ:3.75 (s, 2H, benzylic CH2); 7.4-7.7 (m, 4H, Ar-H); 7.95 (s, 1H, olefinic H).

1. additionwas added in three lots while the reaction mixture
2. stirringThe reaction mixture was further stirred for 30 minutes
3. filtrationafter which the solid was filtered
4. customthe filtrate was evaporated to dryness
5. dissolutionThe residue was dissolved in dry benzene, to which catalytic amount of p-toluenesulfonic acid
6. additionwas added
7. stirringthe reaction mixture was stirred for one hour
8. filtrationThe p-toluenesulfonic acid was filtered off
9. concentrationthe filtrate was concentrated

ORD record

ord-b6a54649e164413f940a06f93c2f9e8d

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05733934