New reaction of thionohydrazides with semithioacetals of thioglycolic acid. One-step synthesis of 2-R-thio-5-R-5H-thiazolo[4,3-b]-1,3,4-thiadiazoles

It was found that aromatic aldehydes, thioglycolic acid and thionohydrazides (methyldithiocarbazate) in equimolar proportions at room temperature in concentrated sulfuric acid are converted into 2-methylthio-5-R-5H-thiazolo[4, 3-bJ-1, 3, 4-thiadiazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 271–273, February. 1996.     

Nitration of 2- and 4-[2-(2-furyl)vinyl]thiazole derivatives

Nitration of 4-methyl-2-[2-(nitro-2-furyl)vinyl]thiazole with a mixture of concentrated nitric and sulfuric acids leads to 4-methyl-5-nitro-2-[2-(3,5-dinitro-2-furyl)vinyl]thiazole. Under the same conditions 2-methyl- and 2-acetamido-4-[1-R-2-(5-nitro-2-furyl)vinyl]thiazoles (R=CH₃, Cl) are nitrated in the 3 position of the furan ring, 2-amino-4-[1-chloro-2-(5-nitro-2-furyl)vinyl]thiazole is nitrated in the 5 position of the thiazole ring and 2-acetamido-5-nitro-4-[2-(2-furyl)vinyl]thiazole undergoes profound changes. Under the influence of a mixture of of nitric acid and acetic anhydride the latter compound is converted quantitatively to the 5-nitro derivative (with respect to the furan ring), whereas 4-[2-(5-nitro-2-furyl)vinyl]thiazole derivatives do not undergo reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 314–317, March, 1977.     

Substitution in barbituric acids

Aromatic and aliphatic aldehydes readily condense with thiobarbituric acid to form 5-arylidenethiobarbituric acids or 5-arylidenebis(thiobarbituric acid)s. A longer time is required for condensation with ketones. The UV spectra of the arylidene derivatives have two absorption bands, with maxima at 240–275 and 280–405 nm, while the spectra of the alkylidene derivatives only one absorption band, with a maximum at 280–295 nm.For part I, see [1].     

Derivatives of quinoline-7-carboxylic acid

The condensation of 4-oxo-1,2,3,4-tetrahydroquinoline-7-carboxylic acid and its 6-chloro analog with aromatic aldehydes has given the corresponding 3-benzyl-4-oxo-1,4-dihydroquinoline-7-carboxylic acids and their 4-chloro derivatives.For Communication II, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp.1115–1118, August, 1970.     

Researches on 2, 1, 3-thia- and selenadiazole

4-Hydroxy-, 4-hydroxy-5-methyl-, 4-hydroxy-7-methylbenzo-2,1,3-thiadiazoles are polymorphous.4-Hydroxybenzo-2,1,3-thiadiazole (I), 4-hydroxy-5-methyl- and 4-hydroxy-7-methylbenzo-2, 1, 3-thiadiazoles (II and III) melt at 114–115°, 110–112°, 100–102° C, respectively, after recrystallization from water [2–4], but after recrystallization from petrol ether [5] they melt at 128–129°, 124–125°, and 119–120° C [5]. In this connection we recrystallized these phenols repeatedly from petrol ether after recrystallizing them from water, and their melting points rose as expected [5]. On the other hand, the compounds with melting points 128–129°, 124–125°, 119–120° C (ex petrol ether), after repeated crystallization from water melted at 114–115°, 110–112°, 100–102° C, respectively.For Part XXXVIII see [1].     

Tetrazoles. 13. Protonation of tetrazolylacetic acids

The protonation of isomeric 1H-, 2H-, and 5H-tetrazolylacetic acids, as well as a series of 5-aryl-1H- and 5-aryl-2H-tetrazolylacetic acids, in aqueous sulfuric acid solutions was studied by IR, UV, and PMR spectroscopy. It is shown that all of the investigated tetrazolylacetic acids are protonated in the tetrazole ring at sulfuric acid concentrations up to 96%; the proton adds to the nitrogen atom in the 4 position.See [1] for communication 12.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1421–1425, October, 1982.     

A kinetic study of the oxidation of 3- and 4-pyridinemethanol,and 3- and 4-pyridinecarboxaldehyde by chromium(VI) in acidic aqueous media

Oxidation of 3-pyridinemethanol (3-pyol), 4-pyridinemethanol (4-pyol), 3-pyridinecarboxaldehyde (3-pyal) and 4-pyridinecarboxaldehyde (4-pyal) by Cr^VI was studied under pseudo-first-order conditions in the presence of a large excess of reductant and at various H_aq ⁺ concentrations; [Cr^VI] = 8 × 10^–4 M, [reductant] = 0.025–0.20 M, [HClO₄] = 1.0 and 2.0 M (I = 1.2 and 2.1 M) or 0.5–2.0 (I = 2.1 M). A linear dependence of the pseudo-first-order rate constant (k _obs) on [reductant] and a parabolic function of k _obs versus [H⁺] lead to the rate law: –d[Cr^VI]/dt = (a + b[H⁺]²)[reductant][Cr^VI], where a and b describe the reaction paths via HCrO₄ ^– and H₃CrO₄ ⁺ species respectively, and are composite values including rate constants and equilibrium constants. The apparent activation parameters were determined from second-order rate constants at 1.0 and 2.0 M HClO₄, at three temperatures within the 293–323 K range. The presence of chromium species with intermediate oxidation states – Cr^V, Cr^IV and Cr^II, was deduced based on e.s.r. measurements and the kinetic effects of Mn^II or O₂ (Ar), respectively. The alcohols were oxidized to the aldehydes, and carboxylic acids and the aldehydes to the carboxylic acids. Chromium(III) was in the form of the [Cr(H₂O)₆]³⁺ complex.     

Synthesis of 2-substituted cinchoninic acid amides and their cyclization into 1,2,4-triazolo[4,3-α]-quinoline-9-and 1,2,4-triazino[4,3-a]quinoline-10-carboxylic acid amides

Substituted amides of 2-hydrazino- and 2-ethylhydrazinocinchoninic acids react with pyruvic acid and its ethyl ester to give amides of 3-methyl-4-oxo-1,2,4-triazino[4,3-a]quinoline-10-carboxylic acid. On reaction with aromatic aldehydes they are converted into amides of 2-ethyl-3-phenyl-2,3-dihydro-1,2,4-triazolo[4,3-a]quinoline-9-carboxylic acid, or, in the case of unsubstituted hydrazines, into amides of 2-arylidene-hydrazinocinchoninic acid, which was oxidized to substituted 1,2,4-triazolo[4,3-a]quinolines.Perm Pharmaceutical Academy, Perm 614600. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 701–705, May, 1977.     

Synthesis and study of 4-aminopyrazolones (5)

Some 4-N-thioureido- and -ureido derivatives are synthesized by reacting 1-phenyl-3-methyl-4-aminopyrazolone(5) hydrochloride at 40–50°, in alcohol solution, with potassium thiocyanate in the presence of sodium acetate plus carbon disulfide, phenylisothiocyanate, and hexamethylenediisocyanate. Acetylation of 1-phenyl-3-methyl-4-aminopyrazolone(5) with C₁–C₈ aliphatic carboxylic acids takes place under more drastic conditions at 100–150°, to give the corresponding 1-phenyl-3-methyl-4-acylaminopyrazolones(5), isolated in 40–60% yield. The UV spectra of the compounds studied are investigated.For Part I, see [1].     

Studies in the field of 2,1,3-thia- and selenadiazoles

The reaction of benzo-2,1,3-thiadiazole with hydroxylamine sulfate in concentrated sulfuric acid at 150° C for 1–10 hr has been studied. It has been shown that under these conditions mixtures of different amounts of 4- and 5-aminobenzo-2,1,3-thiadiazoles are formed.For part LII, see [1].     

Synthesis of heterocyclic sulfides

2-Allylcyclopentane-1-thiol is cyclized by treatment with 75% sulfuric acid and with UV light to 2-methyl-1-thiabicyclo[3, 3, 0]octane and 1-thiabicyclo[4, 3, 0]nonane, respectively. The cyclization is stereospecific.For Part I, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1185–1187, September, 1970.     

Condensed imidazo-1,2,4-azines 22. Alkylation of 5H-imidazo[1,2-b]-1,2,4-triazepin-4-ones

Substituted 5H-imidazo[1,2-b]-1,2,4-triazepin-4-ones react with alkyl (alkenyl) halides, 2-chloroethanol, glycerin dichlorohydrin, haloacetic acids, the methyl ester and amide of monochloroacetic acid in a methanol-sodium methylate system to form N₍₅₎-alkylation products, and with hydroxylamino-O-sulfonic acid to form 5-aminoimidazo[1,2-b]-1,2,4-triazepin-4-one.For Communication 21, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 234–236, February, 1990.     

13C NMR spectra of the bases and conjugate acids of 3- and 5-formyl-,acetyl-, and carbethoxypyrroles

The effect of protonation of the oxygen atom of the carbonyl group and the carbon atom of the pyrrole ring on the ¹³C chemical shifts in a series of 3- and 5-formyl-, 3-acetyl-, and 3-carbethoxypyrroles was studied. The structures of the conjugate acids of the 5-carbethoxypyrroles was established on the basis of measurement of the ¹H and ¹³C NMR spectra. It is shown that protonation of the 5-carbethoxypyr roles occurs at the ring 5-C atom in 28–35 N H₂SO₄. The effect of structural factors and the acidity of the medium on the relative stabilities of the CH conjugate acids of the investigated compounds is examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–492, April, 1979.     

Synthetic analogues of Peganum alkaloids. III. Pentamethylenequinazolones

Monosubstituted 5-, 6-, and 8-methoxy-3,4-dihydro-2,3-pentamethylenequinazolones (1–3) have been syntehsized by the condensation of monosubstituted methoxyanthranilic acids with caprolactam. Demethylation with hydrobromic acid gave the corresponding hydroxy compounds [4–6]. When the 6- and 8-methoxy- and 6- and 8-hydroxy-3,4-dihydro-2,3-pentamethylenequinazolones (2, 3, 5, and 6) were reduced with zinc in hydrochloric acid, the corresponding quinazoline derivatives (7–10) were obtained. The melting points of the basis and their hydrochlorides are given. Some features of their UV, mass, and PMR spectra are reported.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 465–469, July–August, 1986.     

Synthesis and structure of hydrazones obtained from hydrazides of [5-(4-pyridyl)-1,3,4-oxadiazol-2-ylthio]acetic or 2-[5-(4-pyridyl)-1,3,4-oxadiazol-2-ylthio]propionic acids

It has been shown by¹H NMR spectroscopy that hydrazones obtained by the condensation of hydrazides of [5-4-pyridyl)-1,3,4-oxadiazol-2-ylthio] acetic or 2-[5-(2-pyridyl)-1,3,4-oxadiazol-2-ylthio]propionic acids with aldehydes, ketones, and -dicarbonyl compounds exist in DMSO solution as a mixture of stereoisomeric forms.Institute of Chemistry, Vilnius LT-2600, Lithuania. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 966–971, July, 2000.     

4-hydroxy-2-quinolones. 18. Synthesis and antithyroid activity of 1-R-2-oxo-3-(4-oxo-3H-quinazolin-2-yl)-4-hydroxyquinolines

Preparative methods for the synthesis of 1-R-2-oxo-3-(4-oxo-3H-quinazolin-2-yl)-4-hydroxyquinolines based on ethyl esters or nitrites of 1-R-2-oxo-4-hydroxyqidnoline-3-carboxylic acids and anthranilamide or ethyl anthranilate correspondingly were proposed. The antithyroid activity of the compounds synthesized was studied.For Communication 17, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1223–1226, September, 1993.     

One-pot synthesis of 2-amino- 5-aryl -5H-thiazolo[4,3-b]-1,3,4-thiadiazoles

Equimolar mixtures of aromatic aldehydes with thioglycolic acid and thiosemicarbazide in H₂SO₄ transform into 2-amino-5-aryl-5H-thiazolo[4,3-b]-1,3,4-thiadiazoles.Translated fromIzvestiya Akademioi Nauk. Seriya Khimicheskaya, No. 3, pp. 763–764, March, 1996.     

Indole chemistry

Indoles that have alkyl groups in the pyrrole ring are brominated in the 5 position in sulfuric acid. The introduction of an alkyl group into the 7 position may change the orientation and result in the formation of the 6-bromo isomer.See [1] for communication XXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1512–1516, November, 1971.     

Polyfunctional pyrazoles. 3.* Synthesis of 3-(3-aryl-4-formyl-1-pyrazolyl)propionic acids and their amides

3-(3-Aryl-4-formyl-1-pyrazolyl)propionic acids were synthesized by the reaction of 3-aryl-1-(2-cyanoethyl)-4-formylpyrazoles with concentrated hydrochloric acid. They were converted into the corresponding amides by the carbodiimide method.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1483–1486, October, 2004.For Communication 2, see [1].     

Benzindoles. 21. Nitration of 3-formyl[4, 5]-and 3-formyl [6,7] benzindoles

It was established that products of monosubstitution of 4-nitro- and 7-nitro-3-formyl[4,5] benzindoles and products of disubstitution of 4,8-dinitro- and 7,8-dinitro-3-formyl [4,5] benzindoles are formed in low yields in the nitration of 3-formyl [4,5]benzindole with sodium nitrate in concentrated sulfuric acid. Similar nitration of 3-formyl [6,7] benzindole leads to 9-nitro- and 5, 6-dinitro-3-formyl [6,7]benzindoles. The 3-formylnitrobenzindoles obtained were converted to nitrovinyl derivatives by condensation with nitromethane.See [1] for Communication [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–955, July, 1980.