PREPARATIONS 203 elimination of the amino group, because the tribromobenzene so formed is solid, and small quantities can easily be purified by recrystallisation. Required: 2,4,6-Tribromoaniline, 5 g.; absolute ethanol, 40 ml.; dry benzene, 10 ml.; sodium nitrite, 3 g. Dissolve 5 g. of 2,4,6-tribromoanilinc in a hot mixture of 40 ml. of absolute ethanol and 10 ml. of dry benzene con-tained in a 150 ml. wide-necked bolt-head flask. (The benzene is added to increase the solubility of the tribromoaniline.) Now add 2 ml. (3-9 g.) of concentrated sulphuric acid (pre-ferably from a burette or a small pipette) to the hot solution, shaking the latter gently round. Attach the flask to a reflux water-condenser and heat on a water-bath until the clear solution boils. Now detach the flask, add 3 g. of dry powdered sodium nitrite, and return the flask to the condenser but not to the water-bath. Shake the flask vigorously: the heat of the reaction causes the solution to continue boiling for several minutes. When the
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.