反应详情

温度

75 °C

To a suspension of NaH (44.7 mmol) in 100 mL 1,2-dimethoxyethane was added ethyl glycolate (43 mmol) under ice cooling and stirring. The ice bath was removed and stirring was continued at RT. After 30 min, a solution of 3-chloropyridazine-4-carboxylic acid ethyl ester (17.2 mmol) in 40 mL 1,2-dimethoxyethane was slowly added and the mixture was heated to 75° C. for 2 h. The solvent was then evaporated off and the residual solid was redissolved in aq. NaHCO3 solution and EtOAc. The aqueous layer was acidified with AcOH and extracted with DCM (3×). The combined organic layers were dried over MgSO4 and concentrated in vacuo. Purification by CC (KP-SIL™ from Biotage) using EtOAc/MeOH (1/1) gives the desired product as brown solid;

1. customThe ice bath was removed
2. stirringstirring
3. customwas continued at RT
4. customThe solvent was then evaporated off
5. dissolutionthe residual solid was redissolved in aq. NaHCO3 solution
6. extractionextracted with DCM (3×)
7. dry with materialThe combined organic layers were dried over MgSO4
8. concentrationconcentrated in vacuo
9. customPurification by CC (KP-SIL™ from Biotage)