Water → HCID 86720255, Verbindung

Temperatur

77 °C

To a stirred solution of 3-bromo-5-ethylpyrazolo[1,5-a]pyridine (I-17, 2.1 g, 0.0094 mmol) in CCl4 (20 mL) at rt was added NBS (2 g, 0.01 mmol) followed by benzoyl peroxide (1.1 g, 0.004 mmol). The resulting reaction mixture was heated to 77° C. After 2 h, the reaction mixture was allowed to cool to rt and subsequently water (20 mL) was added followed by extraction with dichloromethane (2×20 mL). The combined organic layers were washed with water (1×20 mL), sat NaHCO3 solution (1×10 mL), brine (1×10 mL), dried over Na2SO4 and the solvent was removed under reduced pressure. The resulting crude product was purified by column chromatography over silica gel (petroleum ether/EtOAc, 0-5% EtOAc) to afford 820 mg (29%) of 3-bromo-5-(1-bromoethyl)pyrazolo[1,5-a]pyridine (I-18) as a brown solid. 1H NMR (400 MHz, CDCl3) δ 8.45 (d, J=7.91 Hz, 1H), 7.93 (s, 1H), 7.46 (d, J=1.32 Hz, 1H), 6.90-6.92 (dd, J=1.76, 5.71 Hz, 1H), 5.19-5.24 (m, 2H), 2.08 (d, J=7.04 Hz, 3H); ESI-LC/MS (m/z): [M+H]+ 302.9, [(M+2)+H]+ 304.9, [(M+4)+H]+ 306.9, RT 2.65 min

1. customThe resulting reaction mixture
2. temperatureto cool to rt
3. extractionfollowed by extraction with dichloromethane (2×20 mL)
4. washThe combined organic layers were washed with water (1×20 mL)
5. dry with materialdried over Na2SO4
6. customthe solvent was removed under reduced pressure
7. customThe resulting crude product was purified by column chromatography over silica gel (petroleum ether/EtOAc, 0-5% EtOAc)

ORD-Eintrag

ord-8e08f476c30940c6997cbf58de9cecae

Quelldatensatz

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08871754B2