... Thirty-eight grams of ammonium fluoroborate dissolved in 75 ml of water was chilled and added to the nitrous acid solu- tion with good stirring. (11) J. R. Platt, J. Chem. ... (12) AI Vogel, "Practical Organic Chemistry," John Wiley and Sons, Inc., New York, N. Y., 1956, p 611. ...