反应详情

Prepare 2-chloro-3-(4-trifluoromethylphenyl)-pyrazine in 30% according to the procedure used to make 2-chloro-3-(4-chlorophenyl)-pyrazine. Couple 2-chloro-3-(4-trifluoromethylphenyl)-pyrazine (0.570 g, 2.20 mmol) and piperazine (4.31 g, 50.0 mmol), at 125° C. for 111 min. Cool the reaction to about 70° C., add water (50 mL), stir until the reaction temperature is below 35° C. and dilute with DCM (70 mL). Separate the layers, extract the aqueous layer with DCM (2×70 mL), wash the combined organic layers with saturated aqueous sodium chloride, dry (magnesium sulfate), concentrate and purify (silica gel chromatography, eluting with 0:100 to 1:1 ethyl acetate:hexanes), to give the title preparation (0.384 g, 57%). MS (ES): m/z=309 [M+H]+.

1. temperatureCool
2. customthe reaction to about 70° C.
3. customis below 35° C.
4. customSeparate the layers
5. extractionextract the aqueous layer with DCM (2×70 mL)
6. washwash the combined organic layers with saturated aqueous sodium chloride
7. dry with materialdry (magnesium sulfate)
8. concentrationconcentrate
9. custompurify
10. wash(silica gel chromatography, eluting with 0:100 to 1:1 ethyl acetate:hexanes)
11. customto give the title
12. custompreparation (0.384 g, 57%)