反应详情

温度

0 °C

The mixture of 2-[(3aS,4R,7aR)-2,2-dimethylhexahydro-1,3-benzodioxol-4-yl]-1H-isoindole-1,3(2H)-dione (20) (191.4 mmol, 50.00 g), hydrazine (308.4 mmol, 15.0 mL) in ethanol (500 mL) was refluxed for 4 h. The reaction was monitored by HPLC. HPLC analysis showed the reaction did not go to completion (86% conversion). Additional 3 mL of hydrazine was added to the reaction mixture and refluxed for 2 h. The reaction was cooled to 0° C. and filtered. The filter cake was washed with IPA and dried to afford the desired product 21 (9.52 g, 21% yield, purity in weight: 84% based on NMR). The filtrate was concentrated and the residue was taken up in IPA (about 200 mL). The by-product crystallized and was filtered out, and the filtrate was stripped of volatiles and dried to afford a second crop of the desired product 21(28.46 g, 64% yield). TLC (80% MeOH/EtOAc with 1 drop of acetic acid, stained by ninhydrin dip).

1. temperaturewas refluxed for 4 h
2. temperaturerefluxed for 2 h
3. filtrationfiltered
4. washThe filter cake was washed with IPA
5. customdried