Polymerization of 1,3,5-Tri(1,3,5,7-tetra)-methyl-1,3,5-tri(1,3,5,7-tetra)-10-carbomethoxydecylctri(tetra)siloxane

The cationic and anionic polymerization of 1,3,5-tri(1,3,5,7-tetra)methyl-1,3,5-tri (1,3,5,7-tetra)-10-carbomethoxydecylcyclotri (tetra) siloxane, catalyzed by sulfuric acid and alkali metal naphthalenes, respectively, was studied. With sulfuric acid the polymer yield increased with increasing catalyst concentration, while the molecular weights decreased. With potassium naphthalene the polymerization reaction was first order to monomer, and the molecular weights increased linearly with increasing the percent conversion in accordance with a “living” polymerization. In both cases the polymerization was an equilibrium reaction and the conversion was about 85%. Only low molecular weight polymers were obtained due to steric effects of the bulky long-chain substituents.     

On the regioselectivity of the reaction of cyanothioacetamide with 2-acetylcyclo-hexanone, 2-acetylcyclopentanone, and 2-acetyl-1-(morpholin-4-yl)-1-cycloalkenes

It has been established that the interaction of cyanothioacetamide with 2-acetylcyclohexanone, 2-acetylcyclopentanone, or their enamines (2-acetyl-1-(morpholin-4-yl)-1-cycloalkenes) contrary to the literature data have a non-regiospecific character and leads to the formation of mixtures of 3-cyano-4-methyl-5,6-tri(tetra)methylenepyridine-2(1 H)-thiones and 3-cyano-6-methyl-4,5-tri(tetra)methylene-pyridine-2(1 H)-thiones with a predominance of the latter.     

[Co(3,3-tri)(men)Cl][ZnCl_4]和[Co(3,3-tri)(cmen)Cl][ZnCl_4]两体系配合物的合成及两经式异构体的晶体结构

分别合成了 [Co(3, 3-tri)(men)Cl][ZnCl4]、[Co(3, 3-tri)(cmen)Cl][ZnCl4] (3, 3-tri = N-(3-胺基丙基)-1, 3-丙二胺,men = N-甲基乙二胺,cmen = 1, 2-二胺基-丙烷) 2体系的部分配合物异构体,用单晶 X-射线衍射分析方法解析了2异构体的晶体结构。其中 [Co(3, 3-tri)(men)Cl][ZnCl4] 体系的一异构体Ⅰ的化学简式为 CoCl(C9H27N5)ZnCl4,晶体属正交晶系,空间群 Pca21,a = 16.788(2),b = 7.964(1),c = 14.416(2) 牛琕 =1927.3(4) ?,Dc = 1.747 g/cm3,Z = 4,F(000) = 1032,Mr = 506.91,R = 0.0352,wR =0.0935;[Co(3, 3-tri)(cmen)Cl]2+ 体系的一异构体Ⅱ的化学简式为 CoCl(C9H27N5)ZnCl4稨2O, 晶体属三斜晶系,空间群 P ,a = 9.511(3), b = 9.972(3),c = 11.694(3) 牛琣 = 68.367(5),b = 85.196(6),?= 86.580(5),V = 1026.9(5)?3,Dc = 1.698 g/cm3,Z = 2,F(000) = 536,Mr = 524.92,R = 0.0494,wR = 0.1180。两异构体中 Co3+ 为六配位,晶胞中对映体比例均为1:1。在配合物异构体Ⅰ和Ⅱ中,三元胺以经式排布,三元胺配体(3, 3-tri)仲胺上的氢相对于Cl分别处于顺位(syn-)和反位(anti-);二元胺配体氮(或邻位碳)取代的胺基氮原子(N*)与三元胺配体中的仲氮原子分别处于对位(trans(N*))和邻位(cis(N*))。     

Synthesis of 2-oxo-3-benzothiazolineacetyl chloride (7), 5-chloro-2-oxo-3-benzothiazolineacetyl chloride (8) and derivatives

The reaction of 2-oxo-3-benzothiazolineacetic acid ( 5 ) and the 5-chloro analogue 6 with thionyl chloride afforded the titled compounds 7 and 8 . The reaction of 7 or 8 with substituted hydrazines, amines or substituted anilines, alcohols and mercaptans furnished the hydrazides 9–14 , acetamides and acetanilides 16–21 , esters 26–30 and thiolesters 31–37 , respectively. Alternate routes for the synthesis of hydrazide 15 , acetamides and acetanilides 22–25 and thiolesters 35–36 are described. The reaction of 2-oxo-3(2H)-benzothi-azolineacetonitrile with thioacetic acid under acidic conditions afforded 2-oxo-3-benzothiazolineethanethio-amide (38).     

Derivatives of 1-(2-pyridyl)-4,5,6,7-tetrahydroindazole

In reaction of oxidation of 1-(2-pyridyl)3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydroindazole, the corresponding 4,5-dioxoindazole is obtained, and then 1-(2-pyridyl)-3-methyl-4-carboxy-5-(2-methyl-2-carboxypropyl)pyrazole; in bromination reaction, a series of 5-bromo and 7-bromo derivatives is obtained. From 4,5-dioxoindazole with hydrazides of acids, a series of 4-oxo-5-acylhydrazono derivatives is obtained, and also 1-(2-pyridyl)-3,6,6-trimethyl-4-oxo-5-tosylhydroindazole, which, under the action of caustic, gives the 4-oxo-5-diazo derivative.Riga Technical University, Riga LV-1658. Translated from Khimiya Geterotsiklicheskikh Soerdinenii, No. 3, pp. 351–354, March, 1995. Original article submitted December 29, 1994.     

Iodocyclization of 2-allythio-4(3H)-pyrimidinones

It has been established that the iodocyclization of 2-allythio-4-(3H)-pyrimidinones occurs at the N₍₁₎ nitrogen atom with the formation of 3-iodomethyl-7-oxo-2,3-dihydro-8H-thiazolo[3,2-d]pyrimidinium iodides and triiodides.Chelyabinsk State University, Chelyabinsk, 454136. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 211–213, February, 1995. Original articel submitted January 26, 1995.     

Synthesis and properties of amides of 2-substituted 3-aryl- and 3-pyridylaminoacrylic acids

The reaction of aryl- or pyridylamines with ethyl orthoformate and malonanilic acid gave amides of 2-(N-arylcarbamoyl)-, 2-cyano-, 2-ethoxycarbonyl-3-arylaminoacrylic acids and their corresponding 3-pyridyl analogs. IR and PMR spectroscopy indicates that these compounds exist in the enamine form with strong intramolecular hydrogen bonds. Amides of 3-(2-pyridylamino)-2-ethoxycarbonylacrylic acid cyclize to give amides of pyrido[1,2-a]pyrimidine-3-carboxylic acid, which react with hydrazine hydrate to give amides of 3-aminopyrazole-4-carboxylic acid.Perm Pharmaceutical Institute, 614000 Perm. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 629–633, May, 1994. Original article submitted February 8, 1994.     

1-(1-Phthalazinyl)- and 1-(4methoxyphenyl)-6,6dimethyl-4oxo-4,5,6,7-tetrahydroindazole

2-(1-Phthalazinylhydrazino)methylene-(IIIa) or 2-(1-phthalazinylhydrazino)ethylidene-5,5-dimethyl-1,3-cyclohexanediones (IIIb) were prepared from 1-hydrazinophthalazine and 2 formyl- or 2-acetyldimedone. Cyclization of IIIb in the presence ofp- TsOH gave 1-(1-phthalazinyl)3, 6, 6-trimethyl-4-oxo-4, 5, 6, 7-tetrahydroindazole. Reaction of 4-methoxyphenylhydrazine with 2 formyl- and 2-acetyidimedone gave the corresponding 1-(4methoxyphenyl)-4-oxo-4, 5, 6, 7-tetrahydroindazole. In the case of 2 -formyldimedone the intermediate 2-(4methoxyphenylhydrazinomethylene)-5, 5-dimethyl-1,3-cyclohexanedione was isolated.Riga Technological University, Riga LV-1658. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 708–710, May, 1996. Original article submitted December 31, 1995.     

[Co(3,3-tri)(ibn)Cl]^2^+异构体的2DNMR及其分布规律的研究

利用-维及二维核磁共振谱，如gCOSY和NOESY，对合成的5个[Co(3,3-tri)(ibn)Cl]^2^+几何异构体在溶液中的结构进行了解析，与柱色层方法分离出的五带配合物对照的结果是：b1=m4;b2=m2;b3=m1;b4=m3及b5=f3。利用量子化学从头算方法，从能量角度解释了配合物异构体的分布规律。     

Conversions of methyl esters of (6-methyl-2-methylthio-4-pyrimidinyloxy)- and (3,4-dihydro-6-methyl-2-methylthio-4-oxo-3-pyrimidinyl)acetic acids

A study has been made of nucleophilic reactions (hydrolysis, hydrazinolysis, ammonolysis, reduction) and electrophilic reactions (bromination, nitration) of isomeric methyl esters of (6-methyl-2-methylthio-4-pyrimidinyloxy) acetic acid and (3,4-dihydro-6-methyl-2-methylthio-4-oxo-3-pyrimidinyl)acetic acid. Carboxyl-group derivatives and also derivatives with substituents in position 5 of the pyrimidine ring have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1655–1659, December 1992.     

Novel synthesis of 5,6-dihydro-4H-thieno[3,2-b]pyrrol-5-ones via the rhodium(II)-mediated wolff rearrangement of 3-(thieno-2-yl)-3-oxo-2-diazopropanoates

[reaction: see text] Treatment of thioaryolketene S,N-acetals 12 with Hg(OAc)(2) followed by addition of 2-diazo-3-trimethylsilyloxy-3-butenoic acid alkyl esters 15 in CH(2)Cl(2) at room temperature gave 3-(3-alkylamino-5-arylthieno-2-yl)-3-oxo-2-diazopropanoates 16 in good yields. Subsequent reactions of 16 with a catalytic amount of Rh(2)(OAc)(4).2H(2)O in benzene at reflux afforded a mixture of 5,6-dihydro-4H-thieno[3,2-b]pyrrol-5-ones 18 and the corresponding enols 19 in excellent yields.     

Enantiospecific synthesis of ABC-ring system of A-nor and abeo 4(3→2) tetra and pentacyclic triterpenes

Enantiospecific synthesis of ABC-ring systems of A-nor and abeo 4(3→2) tetra and pentacyclic triterpenes has been accomplished starting from the readily available monoterpene (R)-carvone. (R)-Carvone was used as the B-ring of the target molecules. A lithium-liquid ammonia mediated cyclisation of δ,?-unsaturated ester was employed for the cyclopentannulation at the C-5 and C-6 carbons of carvone and an RCM reaction was employed for the cyclohexannulation to generate the ABC-ring system of A-nor tetra and pentacyclic triterpenes. The strategy has been extended for the synthesis of the ABC-ring system of abeo 4(3→2) tetra and pentacyclic triterpenes.     

Studies on penem and carbapenem. I. Syntheses and oral absorption of ester-type prodrugs of sodium (5R,6S)-2-(2-fluoroethylthio)-6-[(1R)-1-hydroxyethyl]penem-3-c arboxylat e

Acyloxyalkyl esters (2a-d), alkyloxycarbonyloxyalkyl esters (2e-g) and (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl ester (2h) of (5R,6S)-2-(2-fluoroethylthio)-6-[(1R)-1-hydroxyethyl]penem-3- carboxylic acid (1) were synthesized. Enhanced oral absorption was observed in mice reflecting increased lipophilicity, compared with the parent 1 itself. Among them, the ester 2h showed a prolonged plasma level and a large area under the blood concentration-time curve (AUC) in rats. These ester-type prodrugs of penem 1 in phosphate buffer (pH 6.86) were much more stable than those of cephalosporins which easily degraded via isomerization to delta 2 cephalosporins.     

Efficient synthesis of 2,6-disubstituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters

A general procedure is described for the preparation of 6-substituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (6-substituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). These compounds are shown to undergo selective alkylation at the 2-position in moderate to good yields (19-77%) to afford 2,6-disubstituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (2,6-disubstituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters).     

Synthesis and glutamate-agonistic activity of (S)-2-amino-3-(2,5-dihydro-5-oxo-3-isoxazolyl)-propanoic acid derivatives.

(S)-2-Amino-3-(2,5-dihydro-5-oxo-3-isoxazolyl)propanoic acid, (3a) and its analogs (3b--h) were prepared and evaluated for glutamate receptor-agonistic and antifungal activities. Several (S)- and (R)-2-amino-3-isoxazolylpropanoic acid derivatives (3a--d) were synthesized starting with (S)- and (R)-N-tert-butoxycarbonyaspartic acid alpha-methyl esters (4, n = 1) by means of Masamune's chain extension reaction followed by isoxazolone formation with hydroxylamine and subsequent deprotection reactions. Furthermore, (S)- and (R)-N-tert-butoxycarbonylglutamic acid alpha-methyl esters (4, n = 2) were converted to (S)- and (R)-2-amino-4-isoxazolylbutyric acid derivatives (3e-h) via the same sequence of reactions.     

Reaction of the Reformatskii reagent obtained from bromotetrahydrofuran-2-one with 2-oxochromene-3-carboxylic or 3-oxo-3<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">f</Emphasis>]chromene-2-carboxylic acid derivatives

The Reformatskii reagent obtained from 3-bromotetrahydrofuran-2-one reacts with alkyl esters of 6-bromo- and 6,8-dibromo-2-oxochromene-3-carboxylic acid or alkyl esters and N-benzylamide of 3-oxo-3H-benzo[f]chromene-2-carboxylic acid to form alkyl esters of 6-bromo- and 6,8-dibromo-2-oxo-4-(2-oxotetrahydrofuran-3-yl)chroman-3-carboxylic acid or alkyl esters and N-benzylamide of 2,3- dihydro-3-oxo-1-(2-oxotetrahdrofuran-3-yl)-1H-benzo[f]chromene-2-carboxylic acid as a mixture of two diastereomers.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1513–1515.Original Russian Text Copyright © 2004 by Shchepin, Fotin, Shurov.This revised version was published online in April 2005 with a corrected cover date.     

Reactions of Ethyl 2-Amino-5-(2-aryl-2-oxoethylidene)- 4-oxo-4,5-dihydrofuran-3-carboxylates and 2-Amino-5-(2-aryl- 2-oxoethylidene)-4-oxo-4,5-dihydrofuran-3-carbonitriles with Alcohols

Ethyl 2-amino-5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carboxylates and 2-amino- 5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carbonitriles reacted with alcohols in the presence of a catalytic amount of concentrated aqueous HCl to give the corresponding 5-alkoxy-2-amino-5-(2-aryl-2- oxoethyl)-4-oxo-1H-4,5-dihydrofuran-3-carboxylic acid derivatives. A probable reaction mechanism was proposed on the basis B3LYP/6-311G(d) quantum chemical calculations.     

Chemistry of acyl(imidoyl)ketenes. 8*. Thermolysis of 3-alkoxycarbonyl- 5-phenyl-1,2,4,5-tetrahydropyrrolo[1,2-a]- quinoxaline-1,2,4-triones. Structure of 2-(3-oxo-4-phenyl-3,4-dihydro-2-quinoxalinyl)- 2,4-di(ethoxycarbonyl)-6-phenyl-2,3,5,6-tetrahydro- 1h-pyrido[1,2-a]quinoxaline-1,3,5-trione

3-Alkoxycarbonylmethylene-1-phenyl-1,2,3,4-tetrahydro-2-quinoxalones, obtained by the interaction of dialkyl esters of oxaloacetic acid and N-phenyl-o-phenylenediamine, react with oxalyl chloride with the formation of 3-alkoxycarbonyl-5-phenyl-1,2,4,5-tetrahydropyrrolo[1,2-a]quinoxaline-1,2,4-triones. Alkoxycarbonyl(2-oxo-1-phenyl-1,2-dihydro-3-quinoxalinyl)ketenes, generated on thermal decarbonylation of the latter, are stabilized by participation in a [4+2] cyclodimerization reaction with the formation of 2,4-di(alkoxycarbonyl)-2-(3-oxo-4-phenyl-3,4-dihydro-2-quinoxalinyl)-6-phenyl-2,3,5,6-tetrahydro-1H-pyrido[1,2-a]quinoxaline-1,3,5-triones. The crystal and molecular structure of the di(ethoxycarbonyl) derivative have been investigated by X-ray structural analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1501–1506, October, 2004.     

Novel synthesis of 3-aryl-5,6-dihydropyridin-2(1H)-ones

Cyclization of N-3-oxoalkylamides of substituted phenylacetic acids under the influence of bases produces 3-aryl-substituted 5, 6-dihydropyridin-2(1H)-ones. Dehydrogenation of these latter compounds yields substituted pyridin-2(1H)-ones.Omsk State University, Omsk 644077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 812–815 June, 1994. Original article submitted May 6, 1994.     

Azoles and Azines: CXIX. Alkylation of 5,5'-(4-Nitrobenzylidene)bis(2-thiobarbituric) Acid and 5-(4-Nitrophenyl)-2,8-dithioxo-5,7,8,9-tetrahydro-2H-pyrano[2,3-d:6,5-d']dipyrimidine-4,6(1H,3H)-dione with Haloacetic Acids and Their Esters

5,5'-(4-Nitrobenzylidene)bis(2-thiobarbituric) acid and 5-(4-nitrophenyl)-2,8-dithioxo-5,7,8,9-tetrahydro-2H-pyrano[2,3-d:6,5-d']dipyrimidine-4,6(1H,3H)-dione, similar to unsubstituted 2-thiobarbituric acid, readily react with haloacetic acids and their esters to form regioselectively the S-alkylation products. The alternative routes fo 5,5'-(4-nitrobenzylidene)bis[(4-hydroxy-6-oxo-1,6-dihydropyrimidine-5,2-diyl)sulfanyl]diacetic acids, based on condensation of 4,6-dihydroxypyrimidin-2-ylthioacetic acid with carbonyl compounds followed by cyclodehydration to [(5-(4-nitrophenyl)-4,6-dioxo-3,5,6,7-tetrahydro-4H-pyrano[2,3-d:6,5-d']dipyrimidine-2,8-diyl)di(sulfanyl)]diacetic acid derivatives, are less efficient. Alkylation of 2-thiobarbituric acid with ethyl bromoacetate in ethanol in the presence of alkali yields 5-(2-oxo-2,5-dihydro-1,3-thiazol-4-yl)-2-thiobarbituric acid.