Synthesis and Some Reactions of Quinoxalinecarboazides

Chlorination of ethyl(quinoxalin‐2(1H)one)‐3‐carboxylate 1 gave ethyl (2‐chloroquinoxaline)‐3‐carboxylate 2 ;thionation of 1 by P₂S₅ or 2 by thiourea yielded the same product 3 . Reaction of chloro compound 2 or thiocompound 3 with hydrazine hydrate gave pyrazolylquinoxaline 4 . The reaction of ester 1 with thiourea or hydrazine hydrate afforded pyrimido quinoxaline 5 or carbohydrazide 6 ; the reaction of 6 with carbon disulfide in basic medium followed by alkylation afforded oxadiazoloquinoxaline derivatives 7, 8a,b . Carboazide 9 was produced by reaction of 5 with nitrous acid. Compound 9 on heating in an inert solvent, with or without amines, in alcohols or hydrolysis in H₂O undergoes Curtius rearrangments to yield 10‐13 . Reaction of 13 with thiosemicarbazide gave triazoloquinoxaline 14 which on reaction with alkylhalides or hydrazine hydrate yielded 15a‐c while hydrolysis of 13 gave 3‐aminoquinoxalinone 16 which was used as an intermediate to produce 17‐20 .     

Synthesis and Reactions of Some New Thienopyrimidines

4-Methyl-6-mercapto-2-phenylpyrimidine-5-carbonitrile ( 1 ) was reacted with different halo compounds, namely ethylchloroacetate, chloroacetone, bromoacetanilide, p-chlorobromoacetanilide, and p -methoxy chloroacetanilide in ethanol in the presence of sodium acetate yielded the corresponding S-alkylated derivatives ( 2a-e ). The latter compounds underwent cyclization into thienopyrimidines ( 4a-e ) upon treatment with sodium ethoxide in ethanol. The reaction of ( 4a ) with hydrazine hydrate led to the formation of 5-amino-4-methyl-2-phenylthieno[2,3-d]pyrimidine-2-carbohydrazide ( 5 ). Compound ( 5 ) was reacted with a variety of reagents to produce other new thienopyrimidines as well as oxadiazolylthienopyrimidines ( 6, 11 ).     

Synthesis and Some Reactions of Polyols Formals

Synthesis of formals of some polyols such as dipentaerythritol, dietriol and diglycerin was proposed. Based on them, esters and carbamates were obtained.     

Ferrocenecarboselenoic Acid: Synthesis and Some Reactions

The first ferrocenecarboselenoic acid was synthesized and characterized. The existence of tautomeric equilibrium between the selenol (FcCOSeH) and selenoxo forms (FcCSeOH) in polar solvents was proven by ¹H‐, ¹³C‐ and ⁷⁷Se‐NMR spectra. The selenoxo form exists predominantly in a polar solvent at low temperature below –70 °C. Treatment of this acid with lithium, sodium, and potassium hydrides and with rubidium and cesium fluorides gave the corresponding alkali metal ferrocenecarboselenoates in quantitative yields. Treatment with 4‐methylphenyl isocyanate at room temperature led to ferrocenoyl 4‐methylphenylcarbamoyl selenide FcCOSeC(O)NHC₆H₄Me‐4 in high yield. A similar reaction with phenyl isothiocyanate formed a mixture of FcCOSeC(S)NHPh and FcCOSeC(SH)=NPh in moderate to good yield. The carboselenoic acid readily reacted with piperidine to give piperidinium ferrocenecarboselenoate in good yield. Air oxidation of this selenoic acid afforded diferrocenoyl selenide as a major product along with diferrocenoyl diselenide. The structures of the selenide (FcCO)₂Se and diselenide (FcCOSe)₂ were examined by single‐crystal X‐ray analysis.     

Synthesis of Methyl p-Alkoxyphenylcarbamates and Some Their Reactions

Alkylation of methyl p-hydroxyphenylcarbamate with allyl bromide and 1,4-dibromobutane leads to formation of the corresponding methyl p-alkoxyphenylcarbamates. Reactions of methyl p-allyloxyphenylcarbamate with benzaldehyde, p-methoxybenzaldehyde, p-nitrobenzaldehyde, and p-chlorobenzaldehyde oximes in boiling ethanol in the presence of N-chlorobenzenesulfonamide sodium salt yields 3-aryl-5- (p-methoxycarbonylaminophenoxymethyl)-4,5-dihydroisoxazoles. Methyl p-(4-bromobutoxy)phenylcarbamate reacts with morpholine in benzene to give methyl p-(4-morpholinobutoxy)phenylcarbamate.     

Reactions of trimethyl- and triethylaluminium with 2,4,6-tri-t-butylnitrosobenzene

Me₃Al and Et₃Al undergo 1,2-, 1,4- and 1,6-addition to 2,4,6-tri-t-butylnitrosobenzene to give after hydrolysis the corresponding nitrones and oximes. In systems containing Et₃Al the addition products partly undergo further reduction to aromatic amines bearing an ethyl group on the nitrogen atom or the ring. Reduction processes, leading to 2,4,6-tri-t-butylaniline, take place along with the addition reactions.     

Synthesis and Reactions of Some 1-Thiapyran-4-One Derivatives

The preparation of some 3,5-diarylidene-1-thipyran-4-one derivatives (Ia-e) was described. Oxidation of Ia, b and Ie with hydrogen peroxide gave the corresponding dioxides (IIa-c). Reaction of the 1-thiapyran-4-one derivatives with bromine, Grignard reagents, and amines were studied. Structural assignments are supported by spectral (UV, IR, and ¹HNMR) data.     

关于不对称合成反应中若干问题的讨论

在某些经验规则的基础上 ,从旋光特性守恒的角度归纳分析了立体化学反应中反应物和生成物旋光特性的特点 ,并结合该特点的举例讨论了其应用 ,特别是在不对称合成中的应用     

Synthesis and Reactions of Some Substituted Heterocyclic Systems as Anti-arrhythmic Agents

A series of substituted heterocyclic systems were prepared from N ¹-[4-(2-thienylmethylene)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Condensation of the thienylmethylene derivative with guanidine hydrochloride, urea, or thiourea afforded the aminopyrimidine, pyrimidinone, and thioxopyrimidine derivatives. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. Treating of the thienylmethylene derivative with phenylhydrazine or hydrazine hydrate in dioxane afforded N-phenylpyrazoline and a pyrazoline, which was reacted with acetyl chloride in dioxane affording the N-acetyl analogue. The thienylmethylene derivative was reacted with malononitrile or ethyl cyanoacetate in the presence of ammonium acetate to yield the corresponding cyanoaminopyridine and cyanopyrimidone derivatives. Also, it was reacted with hydroxylamine hydrochloride in pyridine to give the oxime derivative, which was cyclized with acetic anhydride. On the other hand, condensation of the thienylmethylene derivative with ethyl cyanoacetate in the presence of sodium ethoxide or cyanothioacetamide gave the cyanopyrane and pyridine thione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.     

Synthesis and Reactions of Some Substituted Heterocyclic Systems as Anti-arrhythmic Agents

Summary. A series of substituted heterocyclic systems were prepared from N ¹-[4-(2-thienylmethylene)phenyl]-5-chloro-2-methoxybenzamide, which was prepared from the corresponding 5-chloroanisic acid (2-methoxy-4-chlorobenzoic acid) as starting material. Condensation of the thienylmethylene derivative with guanidine hydrochloride, urea, or thiourea afforded the aminopyrimidine, pyrimidinone, and thioxopyrimidine derivatives. The latter was condensed with chloroacetic acid to yield a thiazolopyrimidine, which was condensed with 2-thiophenealdehyde to yield the arylmethylene derivative, however, it was also prepared directly from thiopyrimidine by the action of chloroacetic acid, 2-thiophenealdehyde, and anhydrous sodium acetate. Treating of the thienylmethylene derivative with phenylhydrazine or hydrazine hydrate in dioxane afforded N-phenylpyrazoline and a pyrazoline, which was reacted with acetyl chloride in dioxane affording the N-acetyl analogue. The thienylmethylene derivative was reacted with malononitrile or ethyl cyanoacetate in the presence of ammonium acetate to yield the corresponding cyanoaminopyridine and cyanopyrimidone derivatives. Also, it was reacted with hydroxylamine hydrochloride in pyridine to give the oxime derivative, which was cyclized with acetic anhydride. On the other hand, condensation of the thienylmethylene derivative with ethyl cyanoacetate in the presence of sodium ethoxide or cyanothioacetamide gave the cyanopyrane and pyridine thione derivative, which was treated with ethyl chloroacetate affording the ethyl carboxylate derivative. The pharmacological screening showed that many of these compounds have good anti-arrhythmic activity and low toxicity.     

Synthesis and Reactions of Some New 6,7-Dihaloquinolones Bearing Mercapto Groups

Reaction of the 6-chloro-7-fluoroquinoline 7 with methyl 2-mercaptoacetate, methyl 3-mercaptopropionate, or sodium thiophenolate furnished the quinolone derivatives of 3-carbonylsulfanyl-acetic acid methyl ester 8, the propionoate analogue 10, and 3-carbothioic acid S-phenyl ester 11 respectively. Ester 8 was converted into the 3-carbothioic acid S-carbamoyl derivative 9. Analogously, treatment of the 6,7-diflouroquinolone 12 with amino or mercapto precursors led to the formation of 13 and 14 respectively. Reaction of 14 with aqueous NH₃ or H₂O₂/AcOH afforded the acetamide 15 and the sulfoxide 16 analogues, respectively. The 5′-thioalkyl-acyclic quinolone nucleosides 19 and 20 were obtained from reaction of the mesylate derivative 18, prepared from the free nucleoside 17, with the methanthiolate and thiophenolate anions.     

Synthesis and Some Reactions of 4-Aroyl-3-Chloro-6-p-Tolylpyridazines

4-Aroyl-3-chloro-6-p-tolylpyridazines (3a &b) were prepared by the action of phosphorous oxychloride on (2). (3a &b) react with hydrazine hydrate to give the pyrazolinopyridazines (4a &b) and with hydroxylamine hydrochloride to give the isoxazolopyridazines (7a &b), respectively. (4b) was also synthesized by the action of phosphorous oxychloride on the hydrazone (5). The reaction of (3a &b) with primary amines in boiling ethanol gives (8a-e), while their reaction with primary aromatic amines in the presence of solvent gives the Schiff's bases (9a-c).     

Synthesis and Characterization of Some New Star-Shaped Polydentate Ligands from 2,4,6-Trichloro-1,3,5-triazine

Some new star-shaped polydentate ligands were synthesized using 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine as a template and were characterized by infrared, ¹H NMR, and ¹³C NMR spectra and elemental analysis. These products may form polynuclear complexes with metal ions, and the complexes may possess potential applications in the area of electromaterials, optomaterials, magnetic materials, and bio-organic materials.     

2,4,6-三甲基苯甲醛的合成

以1,3,5-三甲苯为原料,用硝酸和醋酸的混酸在5℃下乙酸酐溶液中对其硝化生成2,4,6-三甲基硝基苯(1),收率为90．6％。化合物1由铁粉和盐酸在水、乙醇混合溶剂中进行还原得到2,4,6-三甲基苯胺(2),收率为80．27％。将化合物2制备为盐酸重氮盐(3)后滴加到新制的甲醛肟中反应,浓缩得到2,4,6-三甲基苯甲醛(4),收率为52％。目标化合物结构经质谱、核磁氢谱确证,总收率37．82％,纯度98％。     

Synthesis and structure of 2,4,6-tribromophenoxytetraphenylbismuth

Four new complexes of pentavalent bismuth are synthesized: Ph₃Bi[OC₆H₂(Br₃-2,4,6)]₂, Ph₃Bi[OC₆H₂(Cl₃-2,4,6)]₂, Ph₄BiOC₆H₂(Br₃-2,4,6), and Ph₄BiOC₆H₂(Cl₃-2,4,6). Tetraphenylbismuth aroxides are produced by the disproportionation reaction of ligands from pentaphenylbismuth and triphenylbismuth diaroxides in toluene or from pentaphenylbismuth and phenol. Triphenylbismuth diaroxides are synthesized from phenol, triphenylbismuth, and hydrogen peroxide taken at a molar ratio of 2 : 1 : 1, respectively, in diethyl ether. According to the X-ray diffraction data, the bismuth atom surrounding in 2,4,6-tribromophenoxytetraphenylbismuth has the configuration of a trigonal bipyramid with the aroxyl ligand in the axial position. The Bi-C and Bi-O bond lengths are 2,184, 2.190, 2.234, and 2.514 Å, respectively, and the equatorial CSbC angles are equal to 111.4°, 121.3°, and 121.3°.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 935–938.Original Russian Text Copyright © 2004 by Sharutin, Egorova, Tsiplukhina, Gerasimenko, Pushilin.     

Synthesis and stability of 2,4,6-trinitrobenzylamine

2,4,6-Trinitrobenzylamine was synthesized via 2,4,6-trinitrophenylacetic acid and 2,4,6-trinitrobenzyl isocyanate. The title compound decomposes at room temperature but forms a stable hydrochloride and acetyl derivative.     

Synthesis,Reactions, and Antimicrobial Evaluation of Some Polycondensed Thienopyrimidine Derivatives

Some novel indeno[2,1-b]thiophenes, indeno[1′,2′:4,5]thieno[2,3-d][1,2,3]triazines, indeno[1′,2′:4,5]thieno[2,3-d]pyrimidines, indeno[1′,2′:4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidines, and indeno[1′,2′:4,5]thieno[2,3-d][1,2,4]triazolo[4,3-a]pyrimidines 2–16 were prepared starting with 2-aminoindeno[2,1-b]thiophene-3-carboxylic acid amide ( 1 ). Furthermore, the antimicrobial evaluation of the prepared products showed that many of them revealed promising antimicrobial activity.     

The Synthesis of Sulfinylphthalimides and their Reactions with Some Nucleophiles in Dioxane

Abstract

In this study, some N-(p-substituted-arylsulfinyl)phthalimides (1a–1e) were synthesized. The synthesized compounds were examined with respect to their substitution reactions with sodium ethoxide, sodium methoxide, methylamine, and t-butylamine in dioxane. The substituent effect was investigated at 30.0 ± 0.1 °C. The activation entropy was also studied, and negative ΔS^≠ values were obtained. Configuration inversions were observed in the substitution reactions. This result is in conformity with the S_N2 mechanism.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Characterization of -(p-Substituted-arylsulfinyl)phthalimides 1a–b.]     

Synthesis,Reactions, and Pharmacological Evaluations of Some Novel Pyridazolopyridiazine Candidates

Herein, we report the synthesis, characterization, and preliminary pharmacological activity of a new series of substituted pyrazolopyridazine derivatives. Compound 1 was reacted with ethoxymethylene malononitrile 2 in refluxing ethanol to give the corresponding compound 3 , which was treated with hydrazine hydrate or formamide to give pyrazolo[3,4‐c]pyrazole 4 and pyrazolo pyrimidine 5 derivatives, respectively. Also, compound 3 was reacted with NH₄SCN or carbon disulphide or ethyl acetoacetate to yield the corresponding pyrazolo derivatives 6 , 7 , 8 , respectively. Additionally, compound 3 was reacted with triethyl orthoformat in acetic anhydride to give 9 , which was treated with hydrazine hydrate to give hydrazino derivative 10 . The latter compound transformed into the pyrazolo[4,3‐e][1,2,4]triazolo[1,5‐c]‐pyrimidine 11 via refluxing with acetic anhydride. Finally, compound 9 was reacted with benzoic acid hydrazide or mercapto acetic acid to give compounds 12 and 13 , respectively. The latter compound was treated with refluxing ethanolic sodium ethoxide solution to afford the pyrazolothiazolopyrimidine 14 . Some of the compounds exhibited better activities as anti‐inflammatory and antimicrobial agents than the reference controls. The detailed synthesis, spectroscopic data, anti‐inflammatory, and antimicrobial activities of the synthesized compounds was reported.