反应详情

温度

0 °C

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+).

1. temperatureAfter cooling to −75° C.
2. additionis added dropwise
3. stirringThe reaction is stirred at −75° C. for 30 minutes
4. customprecooled to −75° C.
5. additionis added dropwise
6. stirringthe mixture is stirred at −75° C. for a further 90 minutes
7. additionis added to the reaction mixture, which
8. temperatureis warmed to room temperature
9. customTHF is removed in a rotary evaporator
10. extractionthe aqueous phase is extracted three times with dichloromethane
11. dry with materialThe combined organic phases are dried with MgSO4
12. filtrationfiltered
13. customthe solvent is removed in a rotary evaporator
14. customThe residue is purified on silica gel (eluent ethyl acetate in heptane)