Yu. L. Zborovskii

Synthesis of amino derivatives of triazolopyrimidine

Heterocyclization of 1-(4,6-dimethylpyrimidin-2-yl)-4-R-thiosemicarbazides by the action of methyl iodide in ethanol in the presence of sodium acetate is accompanied by Dimroth rearrangement leading to the formation of 5,7-dimethyl-2-R-amino[1,2,4]triazolo[1,5-a]pyrimidines. Analogous heterocyclization of 4-aryl-1-(4-methyl-6-oxo-1,6-dihydropyrimidin-2-yl)thiosemicarbazides gives 3-arylamino-7-methyl-5-oxo-[1,2,4]triazolo[4,3-a]pyrimidines. The presence in the pyrimidine ring of a carbonyl group capable of forming hydrogen bond with protons of the amino group stabilizes the molecule, thus hampering the Dimroth rearrangement.

Reaction of 4-aryl-1-(4-oxo-3,4-dihydrothieno-[2,3+d]pyrimidin-2-yl)thiosemicarbazides with dimethyl acetylenedicarboxylate

Abstract4-Aryl-1-(4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-2-yl)thiosemicarbazides react with dimethyl acetylenedicarboxylate in methanol to give the corresponding methyl {3-aryl-4-oxo-2-[(4-oxo-3,4-dihydro-thieno[2,3-d]pyrimidin-2-yl)hydrazono]-1,3-thiazolidin-5-ylidene}acetates, whereas in dioxane methyl 5-aryl-amino-2-methoxycarbonylmethyl-3-(4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-2-yl)-2,3-dihydro-1,3,4-thiadiazole-2-carboxylates are mainly formed.

Heterocyclization reactions of 2-(2-propynylthio)-4(1H)-quinazolinone derivatives when treated with electrophilic and nucleophilic reagents

Reaction of the potassium salt of 2-thioquinazolin-4-one with propargyl halides leads to formation of 2-propargylthioquinazolin-4-one derivatives, which undergo heterocyclization when they are treated with electrophilic or nucleophilic reagents and, depending on the nature of the cyclization agent, leads to formation of tricyclic systems with angular or linear structure.

Heterocyclization of N-Hetaryl-N′-(prop-2-en-1-yl)thioureas by the action of sulfuryl chloride

Cyclization of N-hetaryl-N′-(prop-2-en-1-yl)thioureas by the action of sulfuryl chloride leads to the formation of the corresponding 2-hetarylimino-5-chloromethylthiazolidine hydrochlorides which are converted into the free bases by treatment with aqueous sodium sulfite.

Synthesis of fused triazolothienopyrimidine derivatives

Reactions of substituted 1-(thieno[2,3-d]pyrimidin-2-yl)-4-arylthiosemicarbazides with methyl iodide led to the formation of fused triazolothienopyrimidine derivatives.

Synthesis of Thiazino- and Thiazoloquinazolinones by Cyclization of S-(2-Propenyl) Derivatives of 2-Thioxo-2,3-dihydro-4(1H)-quinazolinone

Interaction of potassium salts of quinazolin-2-thiol-4-one with γ-substituted allyl halides gave thiazoloquinazolinones with linear or angular structures depending on the structure of the carbonyl radical. S-Allyl substituted quinazolin-2-thiol-4-one reacted with halogens to give iminium salts of thiazinoquinazolinone with an angular structure. The conversion of these salts to the corresponding bases and thiazoloquinazolinones has been studied.

Halocyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione

Cyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione by the action of iodine, bromine, or sulfuryl chloride gave 2-(2-{4-[4,5-dihydro-5-(halomethyl)-thiazol-2-yl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione hydrohalides which were converted into 2-{2-[4-(5-methylthiazol-2-yl)piperazin-1-yl]ethyl}-1H-benzo[de]isoquinoline-1,3(2H)-dione.

Heterocyclizations of 1-(Benzothiazol-2-yl)-4-phenylthiosemicarbazide

Abstract1-(Benzothiazol-2-yl)-4-phenylthiosemicarbazide reacted with methyl iodide in the presence of sodium acetate in boiling ethanol to give 2,2′-dithiobis[N-(5-methylsulfanyl-4-phenyl-4H-1,2,4-triazol-3-yl)-benzenamine]. The reaction of the title compound with dimethyl acetylenedicarboxylate in dioxane led to the formation of methyl 3-(benzothiazol-2-yl)-2-(2-methoxy-2-oxoethyl)-2,3-dihydro-1,3,4-thiadiazole-2-carboxylate.

Rhodium(III), palladium(II), and platinum(II) complexes with 2-(2-hydroxybenzoyl)-N-methylhydrazinecarbothioamide: Syntheses, structures, and spectral characteristics

The syntheses and spectral (IR, UV-VIS, XPS, and 1H and 13C NMR) characteristics of the rhodium(III), palladium(II), and platinum(II) complexes with 2-(2-hydroxybenzoyl)-N-methylhydrazinecarbothioamide (HBMHCTA) are described. The coordination of HBMHCTA to the central metal ion and its intraligand rearrangement in the complex formation of rhodium(III) ions are studied. The structure of the mixed-ligand complex [Pd(H2L)PPh3] is determined by X-ray diffraction analysis.

Reaction of 1-hetaryl-4-phenylthiosemicarbazides with N,N′-dicyclohexylcarbodiimide

Abstract1,2,4-Triazolo[3,4-b][1,3]benzothiazole, 1,2,4-triazolo[4,3-a]pyrimidine, and thieno[3,2-e][1,2,4]-triazolo[4,3-a]pyrimidine derivatives were synthesized by reactions of 1-hetaryl-4-phenylthiosemicarbazides with N,N′-dicyclohexylcarbodiimide.