反应详情

温度

20 °C

To a solution of diethyl but-2-ynedioate (100 g, 0.588 mol) in a mixture of EtOH (600 mL) and water (600 mL) was added a solution of 1,1-dimethylhydrazine hydrochloride (68 g, 0.705 mol) and NaOH (28.2 g, 0.705 mol) in water (150 mL) dropwise at 0° C. over a period of 20 min. The mixture was stirred at 0° C. for 30 min and 20° C. for 60 min. To the reaction mixture was added EtOAc (800 mL) and stirred. The mixture was separated and the aqueous layer was concentrated. The residue was dissolved in 1N HCl (1 L) and stirred at rt for 90 min. CH2Cl2 (500 mL) was added and the mixture stirred, separated and the aqueous layer was concentrated. The residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1) to give the title compound (17 g, 17% yield) as a white solid.

1. stirringstirred
2. customThe mixture was separated
3. concentrationthe aqueous layer was concentrated
4. dissolutionThe residue was dissolved in 1N HCl (1 L)
5. stirringstirred at rt for 90 min
6. additionCH2Cl2 (500 mL) was added
7. stirringthe mixture stirred
8. customseparated
9. concentrationthe aqueous layer was concentrated
10. customThe residue was purified by chromatography (petroleum ether/EtOAc 10:1-3:1)