反应详情

A mixture of 1.500 mg (6.675 mmol) of 6-(3-chloro-4-hydroxyphenyl)-4,5-dihydro-3(2H)-pyridazinone, prepared by the method of Eur. Pat. Appl. 178,189, 1.010 g (7.34 mmol) K2CO3, and 1.463 g (7.50 mmol) of ethyl 4-bromobutyrate in 30 ml of DMF is heated at 100° C. for 2 hrs under N2. The DMF is removed under vacuum and the residue taken up in 150 ml of EtOAc and 50 ml of water. The organic phase is washed with 50 ml of 5% NaOH, then saturated NaCl solution, dried (MgSO4), and the solvent removed to leave a white solid. This solid is recrystallized from hexane-EtoAc to give 1.711 g of 6-[4-carboethoxypropyloxy-3-chlorophenyl]-4,5-dihydro-3(2H)-pyridazinone as white needles, m.p. 109°-110° C. Yield, 82%.

1. customprepared by the method of Eur
2. customThe DMF is removed under vacuum
3. washThe organic phase is washed with 50 ml of 5% NaOH
4. dry with materialsaturated NaCl solution, dried (MgSO4)
5. customthe solvent removed
6. customto leave a white solid
7. customThis solid is recrystallized from hexane-EtoAc