反应详情

1,2-Dimethoxyethane (130 mL) was added to a mixture of tetrakis(triphenylphosphine)palladium (0) (0.93 g, 0.80 mmol) and 2,6-dichloropyrazine (2.55 g, 17.1 mmol). After 5 min of stirring at room temperature, furan-2-boronic acid (1.91 g, 17.1 mmol) followed by aqueous Na2CO3 (30 mL; 2 M) were added. The mixture was heated at reflux for 1 h [TLC monitoring by SiO2/n-hexane/ethyl acetate (90:10)]. The layers were separated and the light brownish water layer was extracted with dichloromethane (2×200 mL). The combined organic layers were dried (K2CO3), filtered and concentrated in vacuo. The brown-yellow oil obtained was purified by silica gel chromatography (18.5×4 cm) eluting with n-hexane/ethyl acetate (90:10). This furnished 1.47 g (48%) of the title compound as a light yellow solid. HRMS m/z calcd for C8H5ClN2O (M)+ 180.0090, found 180.0092. Anal. (C8H5ClN2O) C, H, N.

1. additionwere added
2. temperatureThe mixture was heated
3. customThe layers were separated
4. extractionthe light brownish water layer was extracted with dichloromethane (2×200 mL)
5. dry with materialThe combined organic layers were dried (K2CO3)
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe brown-yellow oil obtained
9. customwas purified by silica gel chromatography (18.5×4 cm)
10. washeluting with n-hexane/ethyl acetate (90:10)