반응 #40556

반응 방정식

n-Butyllithium

2,2,6,6-tetramethyl-piperidine

3-chloro-6-methoxypyridazine

HCl

NaHCO3

→

6-Chloro-3-methoxypyridazine-4-carbaldehyde

용매

THF

THF

DMF

THF

ethanol

반응 조건

후처리

1. 1
   온도After cooling to −75° C.
2. 2
   workup.ADDITIONis added dropwise
3. 3
   workup.STIRRINGThe reaction is stirred at −75° C. for 30 minutes
4. 4
   기타precooled to −75° C.
5. 5
   workup.ADDITIONis added dropwise
6. 6
   workup.STIRRINGthe mixture is stirred at −75° C. for a further 90 minutes
7. 7
   workup.ADDITIONis added to the reaction mixture, which
8. 8
   온도is warmed to room temperature
9. 9
   기타THF is removed in a rotary evaporator
10. 10
    추출the aqueous phase is extracted three times with dichloromethane
11. 11
    건조The combined organic phases are dried with MgSO4
12. 12
    여과filtered
13. 13
    기타the solvent is removed in a rotary evaporator
14. 14
    기타The residue is purified on silica gel (eluent ethyl acetate in heptane)

실험 절차

n-Butyllithium is added dropwise at −75° C. to a solution of 2,2,6,6-tetramethyl-piperidine in THF. The solution is stirred at 0° C. for 30 minutes. After cooling to −75° C., a solution, precooled to −75° C., of 3-chloro-6-methoxypyridazine in THF is added dropwise. The reaction is stirred at −75° C. for 30 minutes. Subsequently, DMF precooled to −75° C. is added dropwise, and the mixture is stirred at −75° C. for a further 90 minutes. A mixture of conc. aqueous HCl (5 ml), ethanol (20 ml) and THF (25 ml), is added to the reaction mixture, which is warmed to room temperature, and saturated aqueous NaHCO3 solution is slowly added. THF is removed in a rotary evaporator, and the aqueous phase is extracted three times with dichloromethane. The combined organic phases are dried with MgSO4 and filtered, and the solvent is removed in a rotary evaporator. The residue is purified on silica gel (eluent ethyl acetate in heptane). MS (Cl+) m/z 172 (M+).

출처