反应详情

温度

25 °C

A solution of 98% sulfuric acid (121.7 g, 1.22 mol, 0.02 eq) in abs ethanol (1.0 L) was added dropwise to a stirred mixture of 1-(phenylglyoxylyl)piperidine (17.58 Kg, 80.9 mol, 1 eq), p-toluenesulfonhydrazide (16.20 Kg, 87.0 mol, 1.08 eq) and abs ethanol (50 L) at 20-30° C. The obtained mixture was stirred under reflux conditions until 1-(phenylglyoxylyl)piperidine disappeared (˜7 hours, TLC control). The mixture was stirred for 1 hour at 20-30° C. and kept overnight at 4-6° C. The precipitated solid was filtered off, washed on the filter with cold methanol and cold hexane and dried under reduced pressure to a constant weight to yield 28.25 Kg (90.6%) of 1-(phenylglyoxylyl)piperidine p-toluenesulfonylhydrazone with 99.9% purity by HPLC.

1. custom(˜7 hours, TLC control)
2. waitkept overnight at 4-6° C
3. filtrationThe precipitated solid was filtered off
4. washwashed on the
5. filtrationfilter with cold methanol and cold hexane
6. customdried under reduced pressure to a constant weight