(absence of bluish-green coloration when 3mL of *benzene is shaken with a solution of 10mg of isatin in 10mL of conc H2SO4) by refluxing the *benzene (1.25L) for several hours with 40g HgO (freshly precipitated) dissolved in 40mL glacial acetic acid and 300mL of water. The precipitate...
In prepn. of nitrobenzene by isothermal nitration with a HNO3/H2SO4 mixt., sepn. of the nitrobenzene, evapn. of the H2SO4 and recycling of the conc. H2SO4 to the nitration, the H2SO4 is evaporated in a vacuum at 130-195 deg.C to a concn. of 75-92 (80-90)%. - Evapn. ...
Purification MethodsFor most purposes, *benzene can be purified sufficiently by shaking with conc H2SO4 until free from thiophene, then with H2O, dilute NaOH and water, followed by drying (with P2O5, sodium, LiAlH4, CaH2, 4X Linde molecular sieve, or CaSO4, or by passage through a column ...
In prepn. of nitrobenzene by isothermal nitration with a HNO3/H2SO4 mixt., sepn. of the nitrobenzene, evapn. of the H2SO4 and recycling of the conc. H2SO4 to the nitration, the H2SO4 is evaporated in a vacuum at 130-195 deg.C to a concn. of 75-92 (80-90)%. - Evapn. ...