反応 #40556

反応方程式

n-Butyllithium

2,2,6,6-tetramethyl-piperidine

3-chloro-6-methoxypyridazine

HCl

NaHCO3

→

6-Chloro-3-methoxypyridazine-4-carbaldehyde

溶媒

THF

THF

DMF

THF

ethanol

反応条件

後処理

1. 1
   温度After 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
   その他precooled 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
   温度is warmed to room temperature
9. 9
   その他THF is removed in a rotary evaporator
10. 10
    抽出the aqueous phase is extracted three times with dichloromethane
11. 11
    乾燥The combined organic phases are dried with MgSO4
12. 12
    ろ過filtered
13. 13
    その他the solvent is removed in a rotary evaporator
14. 14
    その他The residue is purified on silica gel (eluent ethyl acetate in heptane)

実験手順

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+).

出典