Communications to the Editor 2395 Then, with continuous stirring, the solution was heated at 150°for two hours. The solution became dark red; and on cooling, a tan solid was formed and no liquid remained. This solid is soluble in water and insoluble in ether or benzene. Recrystallization from ethylene dichloride gave a white solid, m.p. 88°, yield 96%.

In 1892-1894 von Miller, Ploechl, and their coworkers (1) reported the addition of hydrogen cyanide to aliphatic oximes and the hydrolysis of the a-hydroxylamino nitriles thus obtained to a-hydroxylamino acids. A few subsequent papers (a, 3) have appeared but work in this field has been largely neglected except for a-hydroxylaminoisobutyronitrile. The last compound has been investigated by several workers (4) because it is the starting point of Piloty's synthesis of porphyrexide. In these studies 20-29% yields were obtained using acetone oxime and a diluted hydrogen cyanide, about three-fifths of the oxime being recovered. If absolute hydrogen cyanide was used, as recommended by von Miller and Ploechl, an oil was formed from which practically no hydroxylaminoisobutyronitrile was obtained.In the present investigations the reactions of butyraldehyde oxime and heptanal oxime with absolute hydrogen cyanide yielded up to 75% and 37% of the expected nitriles, respectively; but the nitriles were seldom obtained in satisfactory purity by this reaction. The best yields were obtained if the operation was interrupted when it changed in color from golden yellon-to orange. At later changes of color from orange to red no nitrile could be isolated. Continued reaction gave rise to black viscous oils and, ultimately, black, coke-like solids. Xeactions in these later stages were quite vigorous. Confirming von Miller and Ploechl (la), we found that neither of the benzaldoximes reacted to form an adduct with hydrogen cyanide, even under a variety of conditions. Also, P-2-furaldosime forms no adduct. Propionaldehyde 2 ! 4dinitrophenylhydrazone was insoluble in hydrogen cyanide and did not react.Butyraldehyde oxime, in contrast, was found to add hydrogen cyanide even from a solution in acetic acid. Furthermore, 2-hydroxylaminovaleronitrile was prepared conveniently and in excellent yield by the reaction of butyraldehyde, hydroxylammonium chloride, sodium cyanide, and potassium dihydrogen phosphate in aqueous solution. Vnfortunately, this last procedure is not general. Although propionaldehyde reacted under these conditions to give 2-hydroxylaminobutyronitrile, heptanal gave only its oxime and none of the nitrile. Formaldehyde reacted under these conditions to give a liquid product which decomposed vigorously at room temperature. Acetone gave only a tar.The yield of 2-hydroxylaminooctanenitrile from heptanal oxime mas increased to 55% by the use of an equivalent of pyridine and an excess of hydrogen cyanide. Small amounts of pyridine (1 or 2%) were not effective. Similarly, pyridine promoted reaction of acetone oxime and hydrogen cyanide to give a 38% yield of a-hydroxylaminoisobutyronitrile, a significant increase over the

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