反应详情

温度

100 °C

A mixture of (S)-ethyl 6-(1-(tert-butoxy)-2-ethoxy-2-oxoethyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (4.5 g, 9.20 mmol), 2-(8-fluoro-5-methylchroman-6-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (3.22 g, 11.04 mmol) and 2N Na2CO3 (9.20 mL, 18.39 mmol) in DMF (100 mL) was degassed and flushed with N2 for 30 min. Tetrakis(triphenylphosphine)palladium(0) (0.744 g, 0.644 mmol) was then added and the reaction was flushed with N2 for another 15 min. The mixture was then heated at 100° C. for 16 h. At this point LCMS indicated completion of reaction and appearance of desired product. After cooling to rt, water was added (50 mL) and the mixture was extracted with ether (2×200 mL). The organic phase was washed with brine (100 mL), dried (Na2SO4), filtered and concentrated in vacuo. The residue was then purified by silica gel chromatography (5-60% EtOAc/hexane) to afford ethyl 6-((S)-1-(tert-butoxy)-2-ethoxy-2-oxoethyl)-7-(8-fluoro-5-methylchroman-6-yl)-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (4 g, 7.58 mmol, 82% yield) as mixture of atrope isomers (approx 10% of minor atrope isomer was present). 1H NMR (500 MHz, CDCl3) δ 7.10 (s, 1H), 6.87 (d, J=10.7 Hz, 1H), 5.00 (s, 1H), 4.41 (qd, J=7.1, 3.1 Hz, 2H), 4.35 (dd, J=5.2, 4.0 Hz, 2H), 4.14 (q, J=7.2 Hz, 2H), 2.80 (s, 3H), 2.79-2.73 (m, 2H), 2.23-2.15 (m, 2H), 1.82 (s, 3H), 1.41 (t, J=7.2 Hz, 3H), 1.22-1.19 (m, 4H), 1.18 (s, 9H). LCMS (M+H)=528.4.

1. customwas degassed
2. customflushed with N2 for 30 min
3. customthe reaction was flushed with N2 for another 15 min
4. customcompletion of reaction and appearance of desired product
5. temperatureAfter cooling to rt
6. extractionthe mixture was extracted with ether (2×200 mL)
7. washThe organic phase was washed with brine (100 mL)
8. dry with materialdried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe residue was then purified by silica gel chromatography (5-60% EtOAc/hexane)