반응 #44296

반응 방정식

2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole

iPrMgCl

→

1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole

수율 80.1%

용매

THF

반응 조건

후처리

1. 1
   workup.STIRRINGto stir for 1 hour at ambient temperature under nitrogen
2. 2
   기타The reaction was quenched with sat. aqueous solution of NH4Cl (10 mL)
3. 3
   workup.ADDITIONwere added
4. 4
   기타The organic layer was separated
5. 5
   추출the aqueous layer was extracted with EtOAc (3×50 mL)
6. 6
   건조dried over Na2SO4
7. 7
   농축concentrated
8. 8
   기타to give the crude product as yellow oil
9. 9
   기타The oil was purified a silica gel column
10. 10
    세척eluting with EtOAc and hexanes

실험 절차

To a solution of 4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole (1.0 g, 3.1 mmol) in anhydrous THF (8 mL) was added iPrMgCl (2M in THF, 3.10 mL, 6.21 mmol) at 0° C. drop by drop under nitrogen. The reaction was stirred for 1 hour at 0° C. under nitrogen. To the solution was added 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.736 g, 4.66 mmoL) at 0° C. and the resulting yellow solution was allowed to stir for 1 hour at ambient temperature under nitrogen. The reaction was quenched with sat. aqueous solution of NH4Cl (10 mL). EtOAc (50 mL) and sat aqueous NH4Cl solution (10 mL) were added. The organic layer was separated, and the aqueous layer was extracted with EtOAc (3×50 mL), dried over Na2SO4, and concentrated to give the crude product as yellow oil. The oil was purified a silica gel column eluting with EtOAc and hexanes to provide 1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole as clear oil (800 mgs, 80% yield). 1H NMR (300 MHz, DMSO-d6) δ 7.91 (s, 1H) 4.48-4.54 (m, 1H) 4.26-4.33 (m, 2H) 3.86-3.90 (m, 1H) 3.66-3.76 (m, 1H) 3.45-3.57 (m, 1H) 3.33-3.39 (m, 1H) 1.33-1.70 (m, 6H) 1.24 (s, 12H).

출처