反应详情

To a suspension of 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl dihydrochloride (2.11 g, 7.77 mmol, 1 eq) in tetrahydrofuran (20 mL) add 1,3,5-trimethyl-1H-pyrazole-4-carbaldehyde (1.61 g, 11.65 mmol, 1.5 eq). Stir for 10 min and add sodium triacetoxyborohydride (4.20 g, 19.40 mmol, 2.5 eq) in one portion. Stir at room temperature under nitrogen for 1 hr., then add further 1,3,5-trimethyl-1H-pyrazole-4-carbaldehyde (0.50 g, 3.6 mmol, 0.47 eq). Stir for 30 min., add saturated aqueous sodium hydrogen carbonate (100 mL) slowly, and then extract with DCM (3×50 mL). Pass the combined DCM extracts through an IST Phase Separator Frit®, concentrate and purify (silica gel chromatography, eluting with 2:98 to 5:95 methanol:DCM), to give the title preparation as a white powder (2.468 g, 98%). MS (ES): m/z=321 [M+H]+.

1. stirringStir at room temperature under nitrogen for 1 hr
2. stirringStir for 30 min.
3. extractionextract with DCM (3×50 mL)
4. concentrationconcentrate
5. custompurify
6. wash(silica gel chromatography, eluting with 2:98 to 5:95 methanol:DCM)
7. customto give the title