反应详情

温度

100 °C

5-Bromo-2-chloropyridine (3.15 g, 16.4 mmol), compound 246 (4.00 g, 16.4 mmol), Pd2(dba)3 (0.749 g, 0.818 mmol), 4,5-bis(diphenylphosphino)-9,9-dimethyl-9H-xanthene (0.947 g, 1.64 mmol) and sodium tert-butoxide (1.82 g, 19.0 mmol) were combined in a screw cap vial and solvated under argon atmosphere with degassed toluene (44 mL). The reaction was briefly sparged with argon, then sealed and stirred at 100° C. After 3 h, the reaction contents were poured into saturated sodium bicarbonate (100 mL) and extracted with 10% methanol in dichloromethane (3×200 mL). The combined organics were dried with sodium sulfate and concentrated in vacuo. Silica gel chromatography (gradient elution 0 to 100% ethyl acetate in hexanes switching to 3% methanol in DCM) afforded compound 247 (5.40 g, 92.7% yield). 1H NMR (500 MHz, CDCl3) δ 0.08 (s, 6 H) 0.91 (s, 9 H) 2.60 (t, J=5.87 Hz, 2 H) 2.70 (br. s., 4 H) 3.20 (d, J=4.40 Hz, 4 H) 3.80 (t, J=6.11 Hz, 2 H) 7.17 (d, J=1.71 Hz, 2 H) 8.02 (s, 1 H) ppm.

1. customcap vial
2. customThe reaction was briefly sparged with argon
3. customsealed
4. customthe reaction contents
5. extractionextracted with 10% methanol in dichloromethane (3×200 mL)
6. dry with materialThe combined organics were dried with sodium sulfate
7. concentrationconcentrated in vacuo
8. washSilica gel chromatography (gradient elution 0 to 100% ethyl acetate in hexanes switching to 3% methanol in DCM)