tert-Butyl acetate → HCID 58095078, Verbindung

Temperatur

-78 °C

To a solution of N,N-diisopropylethylamine (6.6 mL, 38 mmol) in THF (50 mL), n-butyllithium (1.6 mol/L in hexane solution: 24 mL, 38 mmol) was added at −40° C. After being stirred for 30 min, the mixture was cooled to −78° C. To the mixture, was added 1,1-dimethylethyl acetate (5.28 mL, 62.8 mmol) and the mixture was stirred for 40 min at −78° C. To the mixture, was added ethyl 2-methylpyrazolo[1,5-a]pyridine-3-carboxylate (3.64 g, 17.8 mmol) and the mixture was stirred for 1 h at rt. To the mixture, were added a saturated aqueous solution of ammonium chloride (300 mL) and EtOAc (300 mL) and the resulting biphasic mixture was vigorously stirred for 30 min. The organic phase was washed with brine and then dried over anhydrous magnesium sulfate. Insoluble materials were removed by filtration and the filtrate was concentrated under reduced pressure. Column chromatography was performed to yield the title compound (1.58 g, 32%) as a pale yellow syrup. 1H NMR (300 MHz, d6-DMSO) δ: 8.78 (d, J=7.0 Hz, 1H), 8.19-8.10 (m, 1H), 7.61 (ddd, J=8.7, 7.2 and 1.1 Hz, 1H), 7.15 (td, J=7.0, 1.1 Hz, 1H), 3.91 (s, 2H), 2.61 (s, 3H), 1.42 (s, 9H).

1. stirringthe mixture was stirred for 40 min at −78° C
2. stirringthe mixture was stirred for 1 h at rt
3. stirringthe resulting biphasic mixture was vigorously stirred for 30 min
4. washThe organic phase was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customInsoluble materials were removed by filtration
7. concentrationthe filtrate was concentrated under reduced pressure

ORD-Eintrag

ord-cdf73ff9f4da4a1092b37c07d8e7f374

Quelldatensatz

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09139589B2