Summary1,2,3-Triaminoguanidinium chloride was combined with benzaldehyde and hydratropic aldehyde to furnish the corresponding tris(imines), which were converted into 1,2,3-tris(benzylamino)guanidinium salts by catalytic hydrogenation in the former, and by borane reduction in the latter case. The resulting alkyl-substituted triaminoguanidinium salts underwent a threefold carbamoylation with aryl isocyanates to furnish 1,2,3-tris(ureido)guanidinium salts, while p-toluenesulfonyl isocyanate led only to a mono-ureido guanidinium salt. With aryl isothiocyanates, 3-hydrazino-1H-1,2,4-triazole-5(4H)-thione derivatives were obtained. Compounds 7a and 8 show interesting solid-state structures with intra- and intermolecular hydrogen bonds.

Triaminoguanidinium chloride was transformed into 1,2,3-tris(benzylamino)guanidinium chloride (3-Cl) in two steps. Anion exchange allowed the preparation of further salts 3-X. The crystal and molecular structures of 3-Cl, 3-I, 3-CF 3 COO and 3-CF 3 SO 3 were determined. It was found that both the conformation of the cation and the nature of the anion determines the packing in the solid state. Interestingly, three different conformations of the cation were observed in the crystals.

Oxidation of Homocysteine Hydantoin.-Fifty mg. of homocysteine hydantoin was titrated with 2.9 cc. of 0.1 N iodine solution which is 93% of the theoretical. The crystals which precipitated were collected by filtration, dried ^nd gave a m. p. of 201-203°. A mixed m. p. with homocystine hydantoin gave no depression.Oxidation of Cysteine Hydantoin.-Sixty-four and a half mg. of cysteine hydantoin consumed 4.4 cc. of 0.1 N iodine solution which is the theoretical quantity. The crystals were collected on a filter and dried. The com-pound decomposed above 300°and gave a positive disulfide test.

The title compound, C 10 H 20 N 6 (2), was prepared from N,N ,N -triaminoguanidinium chloride. Solvent-and temperature-dependent 1 H NMR spectra indicating prototropic tautomerism were observed in solution. The crystal and molecular structure was determined by X-ray diffraction analysis. The compound crystallizes in the hexagonal space group P6 3 /m. The molecules lie on crystallographic mirror planes parallel to the a,b plane, which are separated from each other by 3.37Å. The threefold crystallographic symmetry of the molecules is due to disorder with positional averaging of individual molecules.

Depending on the reaction conditions, N,N’,N’’-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form either symmetrical N,N’,N’’-tris(N-acyl-N-benzylamido)guanidines 6 or mesoionic 4-amino-1,2,4-triazolium-3-hydrazinides 7. The latter were converted into 1,2,4-triazolium salts by protonation or methylation at the hydrazinide nitrogen atom. Neutral 1,2,4-triazoles 10 were obtained by catalytic hydrogenation of an N-benzyl derivative. Crystal structure analyses of a 4-benzylamino-1,2,4-triazolium-3-hydrazinide and of two derived 1,2,4-triazolium salts are presented.