with aqueous formaldehyde and aromatic amines in benzene or toluene. We explain the effect of substituents in the heterocyclic substrate and the aryl amine on the efficiency of the process within a detailed scheme for one of the possible aminomethylation reaction routes.

CO 3 solution occurs in two steps: in the first step, cleavage of the tetrahydrotriazine ring occurs; and in the second step, opening of the perhydrooxazine ring occurs.

It was found that the aminomethylation of 2-amino-5,5-bis(hydroxymethyl)-1,3-thiazol-4(5H)-one and its spiro analogs using primary amines is accompanied by cyclization at the amidine fragment of the molecule with annelation of a tetrahydrotriazine ring. When using secondary amines the aminomethylation occurs at the exocyclic nitrogen atom.Keywords: 2-amino-5,5-bis(hydroxymethyl)-1,3-thiazol-4(5H)-one, 2-'amino-2-aryl(hetaryl)spiro-[1,3-dioxan-5,5'(4'H)-1',3'-thiazol]-4'-ones, 5-methyl-and 2-amino-5-ethyl-1,3-thiazol-4(5)-ones, aminomethylation.We have previously been able to prepare a 5,5-bis(hydroxymethyl) derivative of 2-amino-1,3-thiazol-4(5H)-one (pseudothiohydantoin) (1a) [1] and synthesize a series of spiro-[1,3-dioxan-5,5'(4'H)-1',3'-thiazole] derivatives (2a-e) from it [2]. Compound 1a is a "truncated" (fragmented) part of the compound 3a molecule which shows high biological activity [3]. This encouraged us to develop a novel method for the preparation of active compound 3a by the aminomethylation of the bis(hydroxymethyl) derivative 1a. This was particularly in view of the fact that the preparation of compound 3a, initially proposed via the direct aminomethylation of pseudothiohydantoin [3,4] is accompanied by the formation of a side reaction product and the yield of the target compound 3a does not exceed 30%. It also seemed suitable for developing a method of preparing homologs of compound 3a through the variation of the amino component in the aminomethylation reaction of compound 1a.With the aim of subsequently studying the biological activity of the newly obtained compounds and revealing a structure-activity relationship we have also synthesized in the work the monohydroxymethyl and spiro analogs of compound 3a using the 1b,c or spiro compounds 2a-e as substrates in the Mannich reaction and tert-butylamine or methylamine as the amino component. The aminomethylation of substrate 1a with secondary cyclic amines also gave the Mannich bases 5a,b, differing from compound 3a in the acyclic structure of the aminomethyl fragment of the molecule. Finally, the hydroxymethylation of the thiazolo[3,2-a]pyrimidine derivative 6 gave compound 7 as the "desaminated" analog of compounds 3a. __________________________________________________________________________________________

The results of cytotoxicity cis-diamine mono- and binuclear complexes of platinum(II) and palladium(II) are presented. The cytotoxicity was investigated by the method of biotesting with Paramecium caudatum and by MTT-assay with human cells: epidermoid carcinoma A431 and minimal transformed aneuploid keratinocytes HaCaT. Cytotoxicity of complexes towards protists is higher than against human cells, however, comparatively, HaCaT is more sensitive than A431 by the treatment all complexes. It is noted that cytotoxicity of palladium(II) complexes is higher than the analogues with platinum(II).

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