For a product of special purity, crystallization from benzene is advisable.
"Organic-Syntheses"
Conant, James Bryant
Most of the benzene may be distilled under ordinary pressure, and the remainder, and any low-boiling impurities, under diminished pressure.
"Organic-Syntheses"
Conant, James Bryant
The benzene solution of phenylhydrazine should be well dried before distilling, since the presence of moisture causes an increased amount of foaming to take place just after the benzene has distilled off.
"Organic-Syntheses"
Conant, James Bryant