Researches on substituted arylamides of dithiocarboxylic acids

Reaction of N-aryl cyanoacetamides with hydrazine hydrate, or its monoaryl-substitution products, gives 3-arylamino-5-aminopyrazoles and 1-aryl-3-arylamino-5-aminopyrazoles. Treatment of aminopyrazoles with aryldiazonium chlorides leads to isolation of the arylazo derivatives. A hypothesis that the pyrazole derivatives synthesized have an amine structure is put forward on the basis of their chemical properties and IR spectra.     

Research on a number of substituted arylamides of dithiocarboxylic acids

Dithiomalonic acid diarylamldes are cyclized to 3,5-diarylamino-1,2-dithiolium halides by oxidation with an equivalent amount of bromine (iodine) in chloroform solution; the same amides are cyclized to 4-bromo-3,5-diarylamino-1,2-dithiolium bromides with excess bromine and to 3-arylamino-5-arylimino-1,2-dithiols in alkaline media with potassium ferricyanide. The behavior of the synthesized substituted 1,2-dithiols with respect to various reagents was studied.     

Researches on substituted arylamides of thiocarboxylic acids

Heating monothio- and dithiomalonic acids with-bromoacetophenone in dry ethanol gives 2,3,4-substituted thiazole derivatives.For Part VI see [1].     

Substituted arylamides of dithiocarboxylic acids

The S-substituted derivatives formed by the reaction of arylamides of cyanothioacetic acid and the esters of arylamides of cyanomonothiomalonic acid with ethyl bromoacetate are cyclized to 2-cyanomethylidene-3-arylthiazolidin-4-ones (III) and 2-carbethoxycyanomethylidene-3-arylthiazolidin-4-ones (VI) rather than to tetrahydrothiophenone derivatives as previously proposed in [1,2].See Zh. Organ. Khim., 4, 234 (1968) for Communication XII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1621–1623, December, 1970.     

Reaction of butyl mercaptan with phenyl esters of dithiocarboxylic acids

Conclusions The reaction of butyl mercaptan with phenyl dithioisobutyrate in the presence of tertbutyl peroxide proceeds with the addition of butylthio radicals at the carbon atom of the C=S bond.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2839–2841, December, 1988.     

Investigations on arylhydrazones of substituted glyoxylic acids

The reaction of arylhydrazones of ethyl cyanoglyoxylate with hydroxylamine hydrochloride in aqueous ethanolic solution in the presence of sodium acetate at the boil has given 3-amino-4-arylazoisoxazol-5-ones. The reaction of arylhydrazones of ethy cyanoglyoxylate with hydroxylamine in the presence of sodium ethoxide in the cold has given arylhydrazones of the amide-oxime of ethyl mesoxalate. The action of acetic anhydride or aryl isothiocyanates on arylhydrazones of the amide oxime of ethyl mesoxalate has given arylhydrazones of the ethyl esters of 5-substituted 1,2,4-oxadiazolyl- or 1,2, 4-thiadiazolylglyoxylic acids.For part XI, see [11].     

Research on arylhydrazones of substituted glyoxylic acids

Reaction of the hydrazides and acetylhydrazides of cyanoacetic acid with aryldiazonium chlorides gives arylhydrazones of the hydrazide and acetylhydrazide of cyanoglyoxylic acid. 2-Acetyl-3-imino-4-arylpyrazol-5-ones and 3-imino-4-arylazopyrazol-5-ones are obtained by cyclizing the arylhydrazones.For Part IX see [1].     

Research on arylhydrazones of substituted glyoxylic acids

Substituted 2-benzalhydrazono-3-phenyl-4-(arylhydrazonochloroformyl)-4-thiazo-lines and 2,2′-azinobis[3-aryl-4-(arylhydrazonochloroformyl)-4-thiazolines], respectively, are formed in the condensation of arylhydrazones of chloromethylgly-oxyloyl chloride with 4-phenylthiosemicarbazones and 1, 6-diarylhydrazodithiocar-bonamides.     

Research on arylhydrazones of substituted glyoxylic acids

3-Aryl-4-(arylhydrazonochloroformyl)-2-[(carbethoxy or carbarnoyl)cyanomethylene]-4-thiazolines were obtained by condensation of arylhydrazones of chloromethylglyoxylic chloride with arylamides of cyanomonothiomalonic acid ethyl ester or amide. The chlorine atom in these compounds is readily exchanged by a hydrazino group to give 3-aryl-4-(arylhydrazonohydrazinoformyl)-2-[(carbethoxy or carbamoyl)cyanomethylene]-4-thiazolines. 2-(Arylhydrazonocarbethoxyformyl)-4-(arylhydrazonochloroformyl)thiazoles were obtained by reaction of arylhydrazones of chloromethylglyoxylic chlorides with arylhydrazones of monothiomesoxalic acid ethyl ester amide. Arylhydrazones of ethyl 1H-tetrazolyl-5-glyoxylate were synthesized by condensation of arylhydrazones of ethyl cyanoglyoxylate with ammonium azide in dimethylformamide.     

Mass spectra of some dithiocarboxylic acid esters

The mass spectra of a variety of aliphatic esters of aromatic dithiocarboxylic acids are reported; their breakdown patterns are compared with those of the corresponding oxygen esters, O-alkyl thioesters and S-alkyl thioesters. Small quantities of O-alkyl thioesters present in alkyl dithioesters can be detected by the appearance of the peak [ArC?O]⁺.     

Synthesis of substituted benzylphosphonic acids

Russian Chemical Bulletin -     

Preparation of substituted gem-dimethylcyclopropanecarboxylic acids

Conclusions A method, based on the addition of Grignard reagent to cyclopropene hydrocarbons, was proposed for the synthesis of alkyl-, phenyl-, and alkenylcyclopropanecarboxylic acids that bear a geminal dimethyl grouping in the ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 669–671, March, 1979.     

Arylamides of substituted thioacetic acids

The reaction of arylamides of monoacetylthioacetic acid with arylhydrazines and hydrazine hydrate has given, respectively, 1-aryl-5-arylamino-3-methylpyrazoles and 5-arylamino-3-methylpyrazoles, the structures of which have been confirmed by independent synthesis and by their IR and UV spectra. It has been shown that, on reacting with arylamides of monoacetylthioacetic acid, nitrogen bases attack first the carbonyl and then the thiocarbonyl group of these compounds, forming substituted pyrazoles.For part III, see [3].     

Arylamides of substituted thiocarboxylic acids

Cyclization of arylamides of acetylthioacetic acid with-bromoacetophenone gives mixtures containing hydrobromides of 2-(acetylmethylene)-3, 4-diarylthiazolines and 2-(acetylmethylene)-3, 4-diarylthiazolines, and from these mixtures hitherto undescribed substituted 4-thiazoline derivatives were isolated by chromatography. 2-(Acetylmethylene)-3-aryl-4-thiazolidones were obtained for the first time by reacting arylamides with acetylthioacetic acid with monochloroacetic acid in the presence of fused sodium acetate in glacial acetic acid.     

Polymorphism in substituted barbituric acids

Of twenty substituted barbituric and thiobarbituric acids studied, nine have been found to exist in polymorphic forms. These are barbital, butethal, amobarbital, pentobarbital, thiopental, phenobarbital, aprobarbital, nostal and kemithal. The different modifications have been studied by X-ray diffraction and infra-red spectrophotometry, and the transition temperature ranges have been determined. The forms found are divided into two groups on the basis of their infra-red spectra. The tautomeric form of the compounds in the solid state is discussed briefly.     

Enzymatic resolution of substituted mandelic acids

A series of substituted mandelic acids were prepared and subjected to enzymatic resolution utilizing Lipase PS ‘Amano’.     

Activated esters of substituted pyrazinecarboxylic acids

N-Amidino-3,5-diamino-6-chloropyrazinecarboxamide ( 1 ) has been shown to be an effective potassium sparing diuretic. Various carboxyl activating agents have been employed with 3-amino-pyrazinecarboxylic acids in an effort to synthesize analogs of 1. Stable enol esters were isolated from a number of such acids and N-t-butyl-5-methylisoxazolium perchlorate ( 12 ). Although strong bases in DMF or DMSO catalyze a competing destruction of the enol ester system, these esters are useful acylating agents for a variety of nucleophilic substrates in less polar media. Amides, esters, and thiol esters are produced in good yields under mild conditions from these activated esters.