反应详情

A solution of 1-acetyl-3-(4-tert-butyldiphenylsilyloxymethyl-3-methylphenyl)methylene-2,5-piperazinedione (6.3 g) in methanol (300 ml) was hydrogenated over 10% palladium-carbon (50% wet) for 4 hours at atmospheric pressure. After removal of the catalyst by filtration, to the filtrate was added hydrazine monohydrate (721 mg). The mixture was stirred for 1 hour at room temperature and concentrated under reduced pressure. The residue was triturated with a mixture of isopropyl ether (200 ml) and n-hexane (400 ml) and the precipitates were collected by filtration, and washed with isopropyl ether to give a crude product. This was purified by flash column chromatography on silica gel using ethyl acetate and a mixture of dichloromethane and methanol (15:1) as eluent to give 3-(4-tert-butyldiphenylsilyloxymethyl-3-methylbenzyl)-2,5-piperazinedione (4.67 g) as a powder.

1. customAfter removal of the catalyst
2. filtrationby filtration
3. additionto the filtrate was added hydrazine monohydrate (721 mg)
4. concentrationconcentrated under reduced pressure
5. customThe residue was triturated with a mixture of isopropyl ether (200 ml) and n-hexane (400 ml)
6. filtrationthe precipitates were collected by filtration
7. washwashed with isopropyl ether
8. customto give a crude product
9. customThis was purified by flash column chromatography on silica gel
10. additiona mixture of dichloromethane and methanol (15:1) as eluent