1. Boon, W. R.Brit. Patent, 546,994;C. A., 1943,37, 5556.
2. Miolati, A.Gazzetta, 1893,23, 1, 578. Levi, T. G.Ibid. Gazzetta, 1931,61, 719.
3. Gabriel, S.Ber., 1910,43, 134, 1283. Rudenberg, K.Ibid. Ber., 1913,46, 3555. Bachstez, M.Ibid. Ber., 1914,47, 3163. Miyamichi, E.J. Pharm. Soc. Japan, 1926, No. 528, 103;C. A., 1926,20, 2679.
4. Hromatka, O.Ger. Patent 670, 131;C. A., 1939,33, 2909.
5. Buchman, Reims and SargentJ. Org. Chem., 1941,6, 764.