Thiocarbamoylation of amine-containing compounds

Thiocarbamoylation of aliphatic amines with tetramethylthiuram disulfide (TMTD) was studied. The reactions were established to proceed according to a two-stage mechanism. In the first stage,S-(thiocarbamoyl)thiohydroxylamines and dimethyl dithiocarbamates are formed. The latter exist in equilibrium with dimethyldithiocarbamic acid, which can undergo decomposition to give dimethylamine and carbon disulfide. In the second stage, several competitive transformations of these intermediates into the final products occur,viz., (1) the reactions of CS₂ with primary amines on heating (70–110 °C) yield mixed and symmetrical thioureas and the reactions of CS₂ with secondary amines give symmetrical dithiocarbamates, and (2) insertion of CS₂ intoS-(thiocarbamoyl)thiohydroxylamines affords thiuram disulfides. Thiuram disulfides formed from primary amines decompose to give isothiocyanates, which are converted into thioureas by condensation with amines, whereas thiuram disulfides which are obtained in the reactions with secondary amines and which cannot form thioureas react with amines analogously to TMTD. For Part 4, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 334–342, February, 2000.     

Thiocarbamoylation of amine-containing compounds

Thiocarbamoylation of 5-aminosalicylic acid with tetramethylthiuram disulfide afforded 5-(N′,N′-dimethylthioureido)salicyclic acid. Treatment of the latter with mineral acids or Ac₂O gave 5-isothiocyanatosalicylic acid whose reaction with ethanolamine yielded 5-[N′-(2-hydroxyethyl)thioureido]salicylic acid. The latter underwent cyclization under the action of TsOH to form 5-(2-thiazolin-2-ylamino)salicylic acid. For Part 2, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2315–2318, December, 1999.     

Reactions of hexaorganyldigermoxanes with O-trimethylsilyl carbamates

Hexa-n-butyl- and hexaisopentyldigermoxanes but not hexaphenyldigermoxane react with O-trimethylsilyl N,N-diethylcarbamate and trimethylsilyl piperidinocarboxylate to give O-triorganylgermyl carbamates.     

N-methyI-N-(triethoxysilylmethyl) andN-methyl-N-(silatran-1-ylmethyl) substituted glycine and alanine

Organosilicon derivatives of glycine, - and -alanine, and -methylalanine were prepared by the reaction of methyl esters of - and -halocarboxylic acids withN-methylaminomethyltriethoxysilane in the presence of triethylamine. The compounds synthesized were converted into the correspondingN-silatran-l-ylmethyl derivatives. Trimethylsilyliodoacetate reacts withN-methylaminomethyltrietoxysilane to give 2,2-diethoxy4-methyl-1-oxa-4-aza-2-silacyclohexane-6-one. Its reaction with triethanolamine leads toN-methyl-N-(silatran-l-ylmethyl)glycine.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 341–343, February, 1995.     

Ni(II)/N,N-dimethylglycine complex equilibrium study

The complex formation of Ni(II) withN,N-dimethyl-glycine in water and in water-methanol has been studied by computer analysis of potentiometric data.

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Gleichgewichtsuntersuchungen der Komplexbildung von Ni(II) mitN,N-Dimethylglycin (Kurze Mitteilung)

Zusammenfassung Anhand der Computer-Analyse von potentiometrischen Daten wurden die Bildungsgleichgewichte von Nickel(II)-Komplexen mitN,N-Dimethylglycin in Wasser und Wasser — Methanol untersucht.

     

Syntheses based on (N,N-difluoroamino)dinitroacetonitrile

High reactivity of the nitrite group in (NN-difluoroamino)dinitroacetonitrile was demonstrated. Based on its reaction with HN₃, a new preparative method for the synthesis of 5-[(N,N-difluoroamino)dinitromethylltetrazole was developed; some derivatives of the latter compound have been obtained.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8. pp. 2056–2058, August, 1996.     

Reactions ofN-nitramines and their trimethylsilyl derivatives withN,N-bis(trimethylsilyloxy)enamines

Trimethylsilyl derivatives of methyl- and ethylnitramine react asN-centered nucleophiles with 2-N,N-bis(trimethylsilyloxy)aminopropene to give trimethylsilyl derivatives of hitherto unknown α-(N-nitro)alkylamino-substituted acetone oximes. As an ambident nucleophile, nonsubstituted methylnitramine reacts with the same enamine to give both a product of N,C-corss-coupling and a product of O,C-cross-coupling,viz., N′-methyl-N-[(2-trimethylsilyloxyimino)propoxy]diazeneN-oxide. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2045–2047, October, 1998.     

Dinitramide and its salts

N,N-Dinitro derivatives of alkylurethanes, benzamide, andp-toluenesulfamide were synthesized for the first time. Their reactions with ammonia afforded the ammonium salt of dinitramide in 44–85% yields.For part 9, seeIzv. Akad. Nauk. Ser. Khim., 1996, 451 [Russ-Chem. Bull., 199645, 433 (Engl. Transl.)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 908–912, April, 1996.     

Synthesis of high-molecular-weight polyamine by radical polymerization ofN,N-diallyl-N-methylamine

The first synthesis of high-molecular-weight poly(N,N-diallyl-N-methylamine) by thermal (at 30 and 50°C) and photoinduced (at 21 °C) radical polymerization ofN,N-diallyl-N-methylamine (DAMA) in aqueous solution in the presence of an equimolar amount of trifluoroacetic acid (TFA) and by polymerization of the newly synthesized equimolar DAMA·TFA salt is reported. Data of¹H NMR spectroscopy indicate that the molecules of the monomer under chosen conditions are in the protonated form. This leads to a decrease in the contribution of the reaction of degradative chain transfer to the monomer and its transformation into effective chain transfer to the monomer. A bimolecular chain termination mechanism was estabilished and the possibility of controlling the polymerization rate and the molecular weight of the polymer was demonstrated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 430–436, March. 2000.     

N, N, N′, N′-四丁基丙二酰胺萃取镧系元素的性能及机理

研究新型萃取剂从硝酸盐介质中萃取分离稀土元素对于后处理工艺具有重要意义。本文报道以甲苯为稀释剂,N,N,N′,N′-四丁基丙二酰胺(TBMA)从硝酸盐介质中萃取铈(Ⅲ)、镝(Ⅲ)、铒(Ⅲ)、镨(Ⅲ)、钐(Ⅲ)、铽(Ⅲ)、铥(Ⅲ)、镱(Ⅲ)的机理。考察了硝酸浓度、TBMA浓度、盐析剂浓度以及温度对上述三价镧系离子分配比的影响。得出萃合物的组成主要是三配体配合物M(NO₃)₃·3TBMA;计算出萃取反应的条件平衡常数、萃取平衡常数。温度效应研究表明萃取反应主要是焓驱动的。对萃取分离系数以及TBMA萃取三价镧系离子的规律进行了初步研究。     

Bis(alkoxyethynyl)-substituted silanes,germanes, and stannanes: synthesis and pyrolysis

Previously unknown bis(alkoxyethynyl)-substituted silanes, germanes, and stannanes were synthesized. Pyrolysis of bis(ethoxyethynyl)-substituted silanes and germanes was studied. Depending on the reaction conditions (pyrolysis in a solvent or vacuum pyrolysis without a solvent), the process affects either one ethoxyethynyl group to give (ethoxyethynyl)silyl(-germyl)ketenes or both ethoxyethynyl groups, affording silyl- and germylbisketenes. Pyrolysis of bis(alkoxyethynyl)dimethylstannanes follows another route, resulting in 1,1-bis(alkoxy)-2,2-bis[(alkoxyethynyl)dimethylstannyl]ethenes.     

Synthesis and chemical transformations of silicon-containing derivatives ofN,N-dimethylhydrazine

Reactions of carbofunctional organosilicon compounds withN,N-dimethyl-N′-trimethylsilylhydrazine andN,N-dimethyl-N′,N′-bis(trimethylsilyl)hydrazine were studied. The composition and structure of the reaction products were found to be dependent on the reagent nature and the reaction conditions. 1,4-Dimethylamino-2,2,5,5-tetramethyl-1,4-diaza-2,5-disilacyclohexane, a first representative of a new type of 2,5-disilapiperazines, was synthesized. A scheme of its formation was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 169–173, January, 1999.     

Synthesis of new N-aryl oxindoles as intermediates for pharmacologically active compounds

Various new N-aryl oxindoles were synthesized as intermediates for the preparation of pharmacologically active 2-(N-arylamino)-phenylacetic acids. Two novel approaches were explored for the construction of diarylamine and N-aryl oxindole core structures, in addition to Buchwald-arylamination and Smiles rearrangement. Condensation of anilines with 2-oxo-cyclohexylidene-acetic acid derivatives and subsequent dehydrogenation is a new and viable method for the preparation of N-aryl oxindoles.     

New activated bisfluoroaromatic compounds

Bis (p-fluorophenylethynyl) derivatives were obtained by the reaction of bisbromoaromatic compounds withp-fluorophenylacetylene in the presence of a Pd catalyst. Subsequent oxidation of these products using an I₂-DMSO system led to new bis(p-fluorophenylglyoxaly)ketones, α-diketones, and heterocyclic compounds. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 810–812, April, 1997.     

S-ArylN,N-dialkylamidothiosulfates, a novel class of sulfenic acid derivatives

A method for the synthesis ofS-arylN,N-dialkylamidothiosulfates, a novel class of sulfenic acid derivatives, was proposed. The method is based on the reaction of arenesulfenyl chlorides withN,N-dialkylamidosulfinic acids or with secondary amines in liquid SO₂ in the presence of triethylamine. In the presence of halogen-containing Lewis acids,S-arylN,N-dialkyl-amidothiosulfates add to the C=C bonds to give aryl β-haloalkyl sulfides. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1484–1487, August, 2000.     

Synthesis and structures of complexes ofN-2-nitroxyethylpicolinamide and 2-(2-pyridyl)-2-oxazoline with PdCl2

The reaction ofN,N′-bis(2-nitroxyethyl)pyridine-2,6-dicarboxamide with PdCl₂ afforded previously unknowncis-(N-2-nitroxyethylpicolinamide-N,N′)dichloropalladium(II) andcis-[2-(2-pyridyl)-2-oxazoline-N,N′]dichloropalladium(II), which were isolated as a cocrystallizate of the molecular compounds. Its structure was established by X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1604–1606, August, 1999.     

Intercalation compounds of phenols and poly-N-vinylcaprolactam

Intercalation compounds of phenols and poly-N-vinylcaprolactam (PVC) form when their aqueous solutions are mixed. Using¹³C NMR and IR spectroscopy complexation was shown to proceed through the formation of hydrogen bonds between the carbonyl groups of the caprolactam moieties and phenolic hydroxyls as well as through displacement of water from the polymer structure and its compaction. The processes of the formation of intercalation compounds of PVC with phenol andtert-butyl alcohol were compared.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2251–2255, September, 1996.     

Chemistry of <Emphasis Type="Italic">N,N</Emphasis>-bis(silyloxy)enamines 7. Quaternization of tertiary amines and nitrogen-containing heterocycles by <Emphasis Type="Italic">N,N</Emphasis>-bis(silyloxy)enamines

Coupling of N,N-bis(silyloxy)enamines with tertiary amines and nitrogen-containing heterocycles affording the corresponding functionalized ammonium or iminium salts was studied. The area of its application was determined, and optimal procedures for the synthesis of the target products were proposed. The mechanism including the formation of conjugated nitroso alkene or a silylnitrosonium cation as key intermediates is discussed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2137–2143, October, 2004.     

Regioselective Deprotection of 1,3-Dibenzyl-5-（N,N-dimethylamino）-6-phenylethyluracil

The deprotection of 1,3-dibenzyl-5-（N,N-dimethylamino）-6-phenyl-ethyluracil I was investigated. A practical, regioselective N3 deprotection of compound I was performed with excellent yield using cyclohexene as a hydrogen donor.     

N-对甲基苯基-N′-（2-吡啶基）脲的低温热容及热分析

通过低温量热和热分析方法,测定了N-对甲基苯基-N′-（2-吡啶基）脲(以下简称NPMPN′2PU)的低温热容和热力学性质.通过对NPMPN′2PU进行低温量热,得到了NPMPN′2PU在80～370 K 温区的热容曲线,热容曲线光滑,没有任何热异常现象,由此实验热容数据计算出NPMPN′2PU在这段温区内的热力学数据.从DSC实验结果发现, NPMPN′2PU熔化峰值出现在173.86 ℃,熔化焓为204.45 kJ•mol－1.紧接熔化峰后NPMPN′2PU开始分解,分解峰只有一个,分解峰值温度为226.11 ℃.TG和DTG的实验结果表明,NPMPN′2PU失重的峰值为227.2 ℃,这些结果与DSC实验结果吻合.