PREPARATIONS 285 added too rapidly, check excessive boiling of the ether by immers-ing the flask in cold water for a few minutes, taking care, however, not to stop the reaction entirely. When the addition of the bromobenzene is complete and the ether is boiling gently, reheat the flask on the water-bath for a further 15 minutes to ensure completion of the reaction: the solution will now be slightly dark in colour, and only a trace of metallic magnesium should remain. Now remove the flask from the water-bath, and slowly add a solution of 5 ml. (5-2 g.) of dry ethyl benzoate in 15 ml. of anhydrous ether down the condenser in small quantities at a time, mixing the contents of the flask thoroughly between each addition. When the boiling of the ether again subsides, return the flask to the water-bath and reheat for a further 15 minutes. Then cool the mixture in ice-water, and carefully pour off the ethereal solu-tion into a mixture of about 60 ml. of dilute sulphuric acid and ioo g. of crushed ice contained in a flask of about 500 ml.
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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.