1. E. Ware, Chem. Rev.46, 403 (1950).
2. However,A. Novelli, Z. M. Lugones, andP. Velasco [An. Asoc. quím. argent.30, 225 (1942)] converted (60% yield) the 3-methyl-5,5-(2'-isopropyl-5'-methyl-pentamethylene)hydantoin into its 1-methyl derivative by means of dimethyl sulphate and sodium hydroxide in ethanol.
3. E. Cattelain andP. Chabrier, Bull. Soc. chim. Fr.1947, 639, reported the preparation of 1-methyl-5,5-diphenylhydantoin (and other 1-alkyl derivatives) from 5,5-diphenyl-2-thiohydantoin, but other workers5 identified the product as the 3-methyl-5,5-diphenylhydantoin.
4. H. C. Carrington andW. S. Waring, J. chem. Soc.1950, 354, transformed 5,5-diphenylhydantoin into 2-ketq-4-methylthio-5,5-diphenyl-2,5-dihydro-glyoxaline, which by methylation and subsequent hydrolysis of the product led to 1-methyl-5, 5-diphenylhydantoin.
5. O. O. Orazi andR. A. Corral, Tetrahedron15, 93 (1961).