The reactions of sulfamides with 4,5 dihydroxyimidazolidin 2 ones were studied at ambient and high pressure. The previously unknown derivatives of 5(3H) oxotetrahydro 1H imidazo [4,5 c] [1,2,5]thiadiazole 2,2 dioxide, viz., sulfo analogs of tetrahydroimidazo[4,5 d]imidazole 2,5 (1H,3H) diones (glycolurils), were synthesized. The structures of some of these compounds were established by X ray diffraction. The high pressure reactions performed under conditions of solvent phase transitions afforded also N (1,3 diethyl 5 hydroxy 2 oxoimidazolidin 4 yl) N,N´ dialkylsulfamides. Among these compounds, a new conglomerate was found. Key words: α ureidoalkylation, 5(3H) oxotetrahydro 1H imidazo[4,5 c][1,2,5]thiadiazole 2,2 dioxides, N (1,3 diethyl 5 hydroxy 2 oxoimidazolidin 4 yl) N,N´ dialkylsulfamides, X ray diffraction study, conglomerate.Imidazolidin 2 one derivatives exhibit antispasmodic, analgesic, neurotropic, etc. activities. 1-4 Substituted 1,2,5 thia diazolidine 1,1 dioxides inhibit the enzymes human leu kocyte elastase and cathepsin G and have antiulcer and antispasmodic activities. 5-7 Hence, the design of potent biologically active compounds containing the annulated imidazolidine and thiadiazolidine rings continues to be an important problem.Earlier, we have shown for some examples that the simplest procedure for the synthesis of such compounds is based on the condensation of 4,5 dihydroxyimidazolidin 2 ones (DHIs) 1 with sulfamides. 8-11 First representatives of 1,3,4,6 tetraalkyl 5(3H) oxotetrahydro 1H imidazo [4,5 c][1,2,5]thiadiazole 2,2 dioxides 2a,b were synthe sized in 52% and 8% yields, respectively, in water at pH 1, atmospheric pressure, and 80-90 °C. 8,9 Under these con ditions, unsubstituted sulfamide gives 4,4´ sulfonyl diiminobis(1,3 dialkylimidazolidin 2 ones) 3a,b in 40-45% yields. 9,10 Tetrahydroimidazothiadiazoles 2c,d were synthesized in 45-63% yields by condensation of 1a,b with unsubstituted sulfamide at pH 5-6 and 60 °C. 8 More recently, 12 we have found that the acid catalyzed reac tions of 1 alkylsulfamides with DHIs in methanol afford compounds containing the imine bond, viz., 1,3 dialkyl 4 (alkylaminosulfonylimino)imidazolidin 2 ones 4a-h.In continuation of our studies aimed at extending the range of potent biologically active monosulfo analogs of glycolurils 2 containing different numbers of alkyl sub stituents at the nitrogen atoms, here we report a compre hensive study of the condensation of 1a-d with sulfamides 5a-f at ambient and high pressure and the structural investigations of the resulting compounds by different physicochemical methods, including X ray diffraction.Under atmospheric pressure, the reactions of 1a-d with sulfamides 5a-f were carried out at 80-90 °C and pH 1 in water for 0.5-1 h (conditions A), at 60-70 °C in H 2 O at pH 6 (conditions B), or in MeOH both in the presence of acids (conditions C) and in their absence (conditions D) (Scheme 1). In addition, analogous reac tions were studied at high pressure using different modes.Di N substituted tetrahydroimidazothi...
