7H-Cyclopenta[b]pyridin-7-one, 5,6-dihydro-

Uses

5,6-Dihydro-7H-cyclopenta[b]pyridin-7-one, is an intermediate for the synthesis of pharmaceutical and biological compounds. It can be used for synthesis of new propargylated 1-pyrindane derivatives as Rasagiline (R126000) analogues, used as an antiparkinsonian agent.

Synthesis

General procedure for the synthesis of 5,6-dihydro-7H-cyclopenta[b]pyridin-7-one from the compound (CAS: 74701-35-2): 5-benzylidene-6,7-dihydro-5H-[1]pyrazine (12.18 g, 58.8 mmol) was dissolved in 200 mL of mixed solvent of MeOH:CH2Cl2 (1:1), and the ozonolysis reaction was performed at 7 psi and 1.5 amperes for the ozonolysis reaction. Upon completion of the reaction, the reaction mixture was quenched with thiourea, filtered and concentrated. The product was purified by column chromatography using hexane:EtOAc (4:1) as eluent to afford 5.96 g (76% yield) of 5,6-dihydro-7H-cyclopenta[b]pyridin-7-one. The structure of the product was confirmed by 1H NMR (300 MHz, CDCl3): δ 2.75-2.82 (m, 2H), 3.15-3.22 (m, 2H), 7.47 (q, J = 4.40, 3.52 Hz, 1H), 7.91 (d, J = 8.79 Hz, 1H), 8.79 (d, J = 5.28 Hz, 1H).

References

[1] Patent: US2008/255239, 2008, A1. Location in patent: Page/Page column 32
[2] Journal of Organic Chemistry, 1984, vol. 49, # 12, p. 2208 - 2212
[3] Journal of Medicinal Chemistry, 2008, vol. 51, # 3, p. 392 - 395