A novel series of 1-[S-TAG-N-substiturtedthioamido]dicyandiamides (5a-f) have been synthesized successfully by refluxing tetra-O-acetyl--D-glucopyraosylbromide (4) with cyanoamidinosubstitutedthiocarbamides (3a-f) in 2-propanol for 3h. The structure of these newly synthesized compounds have been established on the basis of chemical characteristics, elemental analysis, IR and 1 H-NMR spectral analysis.

Recently in this laboratory a novel series of Hector's bases (1, 2, 4-thiadiazolidine) had been synthesised. 1-substituted-3-formamidinothiocarbamides (1a-f) and 1,3-bis(N-substituted-thioamido)guanidines (1g-l) were oxidatively cyclised by using aqueous bromine as oxidizing agent in chloroform medium to synthesised yet new series of Hectors bases, viz; 3-imino-5-substituted imino-1,2,4-thiadiazolidine (2a-f) and 3-substituted thioamidoimino-5-substitutedimino-1,2,4-thiadiazolidine (2g-l), respectively The oxidative cyclisation of (1a-l) was also carried out by making use of H 2 O 2 in concentrated HCl as the oxidizing agent. The Hector's bases isolated in these reactions were characterised on the basis of conventional elemental analysis, chemical characteristics and IR and 1 H-NMR spectral analysis.

Guanidine was successfully interacted with acetoacetic ester to synthesize 2-amino-4-hydroxy-6-methylpyrimidine (L 1 ) which on further treatment with phenylisothiocyanate furnishes 1-(4-hydroxy-6-methylpyrimidino)-3-phenylthiocarbamide (L 2 ). The interactions of Cu(II), Cd(II), Cr(II) metal ions with L 1 and L 2 have been studied at 0.1 M ionic strength in 70 % Dioxane-water mixture by Bjerrum method as adopted by Calvin and Wilson, It is observed that Cu(II), Cd(II), Cr(II) metal ions form 1:1 and 1:2 complexes with ligands (L 1 and L 2 ). The data obtained were used to estimate and compare the values of proton-ligand stability constant (pK.) and metal-ligand stability constants (log k).The effect of substituents were studied from estimated data (pK & log k).