Thieno[2,3-d]pyrimidin-4-ones 1. Condensation of 2,3-dimethyl- and 2,3-tri-, 2,3-tetra-, and 2,3-pentamethylene-7,8-dihydro-pyrrolo[1,2-a]thieno[2,3-d]pyriminidin-4(6H)-ones with aromatic aldehydes and furfural

2,3-Dimethyl- and 2,3-tri-, 2,3-tetra-, and 2,3-pentamethylene-substituted 8-arylidene-6,7-dihydro-pyrrolo[1,2-a]thieno[2,3-d]pyrimidin-4-ones were synthesized by the reaction of 2,3-dimethyl- and 2,3-tri-, 2,3-tetra-, and 2,3-pentamethylene-7,8-dihydropyrrolo[1,2-a]thieno[2,3-d]pyrimidin-4(6H)-ones with benzaldehyde, its 4-dimethylamino-, 3,4-dimethoxy-, and 3,4-methylenedioxy derivatives and also furfural in the presence of NaOH.     

Head-to-head polymers. XV. A facile synthesis of 2,3-disubstituted succinates and butanediols-1,4

A synthetic approach that makes symmetrically 2,3-dialkyl-substituted succinates and compounds prepared from 2,3-dialkyl-substituted succinates easily available has been developed. Coupling of α-bromoalkanoic esters with a zinc/copper couple produced in about 40% yield 2,3-disubstituted succinates which were reduced with LiAlH₄ to 2,3-disubstituted butanediols-1,4 in nearly quantitative yields. Some 2,3-disubstituted butanediols-1,4 were cyclodehydrated under reduced pressure with KHSO₄ to 3,4-disubstituted tetrahydrofurans or acetylated and the diacetyl compounds pyrolyzed at 525°C to 2,3 disubstituted butadienes-1,3. The length of the alkyl chains of the 2,3-dialkylsuccinates and consequently the 2,3-dialkylbutanediols-1,4 ranged from C₂ to C₁₆. 2,3-Disubstituted butanediols-1,4, 2,3-disubstituted butadienes-1,3, and 3,4-disubstituted tetrahydrofurans are interesting monomers for polymerization experiments.     

Optimization of synthesis conditions of 2,3-dimethylbutadiene

Catalytic dehydration of anhydrous 2,3-dimethyl-2,3-butanediol and 2,3-dimethyl-2,3-butanediol hexahydrate under atmospheric pressure was studied. Effect of temperature and reagent flow rate on the yield of 2,3-dimethylbutadiene was examined. The optimal conditions of these processes were found.     

Benzofuro[2,3-d]pyridazines IV. Etude de la chloro-4 benzofuropyridazine

[1] Benzofuro[2,3-d] pyridazone was synthesized by three methods namely8: catalytic dehalogenation of the 4-chlorobenzofuro [2,3-d] pyridazone; removal of the hydrazono group of 4-hydrazinobenzofuro [2,3-d] pyridazine and desulphurization of benzofuro [2,3-d] pyridazine and desulphurization of benzofuro [2,3-d] pyridazine-4(3H) thione. The 4-substituted derivatives were obtained by nucleophilic attack of the 4-chlorobenzofuro[2,3-d] pyridazine. Tetrazolo[1,5-b]- and s-triazolo-[1,2-b] benzofuro [2,3-d] pyridazones. The structural assignment of the benzofuro[2,3-d]pyridazones was made by the Noe effect.     

羟基功能化离子液体与溶菌酶相互作用的研究

采用荧光光谱和紫外吸收光谱研究了羟基功能化离子液体1-(1,2-二羟基丙基)-3-甲基咪唑氯盐([2,3-dhpmim]Cl)、1-(1,2-二羟基丙基)-3-甲基咪唑四氟硼酸盐([2,3-dhpmim]BF4)、1-(1,2-二羟基丙基)-3-甲基咪唑六氟磷酸盐([2,3-dhpmim]PF6)与溶菌酶的相互作用。研究发现此3种离子液体对溶菌酶的荧光猝灭均为静态猝灭;同步荧光显示离子液体与溶菌酶肽链上的色氨酸残基作用,色氨酸残基微环境发生改变;结合常数和结合位点数按照[2,3-dhpmim]Cl、[2,3-dhpmim]BF4、[2,3-dhpmim]PF6顺序依次增大,并随温度的升高而增大。     

Thermal degradation of bromine-containing polymers. Part 9—Copolymers of 2,3-dibromopropyl methacrylate and 2,3-dibromopropyl acrylate with styrene

The products of the thermal degradation of copolymers of styrene (S) with 2,3-dibromopropyl methacrylate (2,3-DBPM) and 2,3-dibromopropyl acrylate (2,3-DBPA) have been analysed quantitatively using thermal analysis, infra-red spectroscopy, mass spectrometry and gas-liquid chromatography. The products are generally similar to those which result from the degradation of the two homopolymers and no significant interaction occurs between the two types of units in the polymer chains. The only abnormal feature is the fact that the yield of 2,3-DBPA increases as the 2,3-DBPA content of copolymers of 2,3-DBPA and S decreases but this is consistent with previous observations in related copolymer systems.     

Chemistry of 2-Methylene-2,3-dihydrofuran-3-ones: XVIII. Reaction of Oxalyl Chloride with Acetophenone and Dibenzoylmethane

Treatment of acetophenone and dibenzoylmethane with excess oxalyl chloride gave heterocyclization products, 2-(3-oxo-5-phenyl-2,3-dihydrofuran-2-ylidene)-5-phenyl-2,3-dihydrofuran-3-one and a mixture of 4-benzoyl-5-phenyl-2,3-dihydrofuran-2,3-dione with 4-benzoyl-2-dibenzoylmethylene-5-phenyl-2,3-dihydrofuran-3-one.     

Stereoselective synthesis of 2,3-diamino-2,3-dideoxy-β-D-mannopyranosyl uronates

With the aim to find an efficient synthetic procedure for the construction of 2,3-diamino-2,3-dideoxy-β-D-mannuronic acids, we evaluated three mannosyl donors: (S)-phenyl 4,6-di-O-acetyl-2,3-diazido mannopyranoside, (S)-phenyl 2,3-diazido-4,6-O-benzylidene mannopyranoside, and (S)-phenyl 2,3-diazido mannopyranosyl methyl uronate. The first two mannosylating agents are rather unselective or slightly α-selective in their condensation with three different acceptors. The mannuronic acid donor on the other hand reliably provides the desired β-mannosidic linkage. A mechanistic rationale is put forward to account for the different behavior of the three donor types. Suitably protected 2,3-diazido mannuronic acids were employed to construct the all-cis-linked tetrasaccharide repeating unit of the capsular polysaccharide of Bacillus stearothermophilus , featuring two 2,3-diacetamido-2,3-dideoxy-β-D-mannuronic acids.     

Dioxodihydrobenzo[b]furoindoles

The synthesis and some properties of the isomeric 2,3-dioxo-2,3-dihydro-1H-benzo[b]furo[2,3-g]- and 2,3-dioxo-2,3-dihydro-1H-benzo[b]furo[3,2-g]indoles are described. Georgian Technical University, Tbilisi 380075. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, 627–630, May, 1999.     

Synthesis and structure of 6-bromo-4-hydroxy-2,3-tetramethylene-3,4-dihydroquinazoline and its mixed crystal with 4-hydroxy-2,3-tetramethylene-3,4-dihydroquinazoline

Bromination of the alkaloid 2,3-tetramethylene-3,4-dihydroquinazoline by N-bromosuccinimide was studied. It was shown that either 4-hydroxy-2,3-tetramethylene-3,4-dihydroquinazoline or 6-bromo-4-hydroxy-2,3tetramethylene-3,4-dihydroquinazoline was formed depending on the ratio of reagents. Oxidation of 2,3tetramethylene-3,4-dihydroquinazoline by KMnO₄ produced 4-hydroxy-2,3-tetramethylene-3,4dihydroquinazoline. The crystal structures of 6-bromo-4-hydroxy-2,3-tetramethylene-3,4-dihydroquinazoline and its mixed crystal with 4-hydroxy-2,3-tetramethylene-3,4-dihydroquinazoline were studied by x-ray structure analysis. The enantiomeric molecules in all crystal structures formed associates owing to two opposing OH...N1 H-bonds.     

beta-Glycosides of 2,3-Diazido-2,3-dideoxy-D-mannose, a Synthetic Precursor of a Rare Bacterial Cell-Wall Building Unit

2,3-Diazido-2,3-dideoxy-beta-D-mannopyranoside derivatives were synthesized in order to prepare beta-glycosides of 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, a rare moiety of bacterial oligosaccharides. A direct glycosyl donor, 4,6-di-O-acetyl-2,3-diazido-2,3-dideoxy-alpha-D-mannopyranosyl bromide, was prepared, and its synthetic capacity was tested in glycosylation reactions. An indirect route was also elaborated: 3-azido-3-deoxy-beta-D-glucopyranosides were converted into beta-D-mannopyranosides. The cis vicinal diazido function successfully tolerated the conditions of mild acidic hydrolysis, tritylation, Jones oxidation, TEMPO oxidation, acetolysis, and bromination with TiBr(4).     

Interaction of benzothieno[2,3-c]pyrylium salts with hydrazine. Derivatives of 5H-[2,3]benzothieno[2,3-e]diazepines

A study has been made of the reaction of 1,3-disubstituted bezothieno[2,3-c]pyrylium salts with hydrazine. It has been shown that 1,3-dialkyl-substituted benzothieno[2,3-c]pyrylium salts interact with hydrazine to give N-amino-1,3-dialkylbenzothieno[2,3-c]pyridines. The presence of a pyrylium ring on one of the positions of the phenyl group leads to a mixture of N-amino derivatives and 5H-[2,3]benzothieno[2,3-e]diazepines. In contrast, 1,3-diphenylbenzothieno[2,3-c]pyrylium perchlorate gives exclusively 5H-[2,3]benzothieno[2,3-e]diazepine.L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Tar Chemistry, National Academy of Sciences of Ukraine, Donetsk 340114. Translate from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp 1137–1140, August, 1998.     

Formation of condensed sulfur-nitrogen-containing heterocyclic compounds through transformations of allyl-2-pyridylsulfide and -sulfoxide

Allyl-2-pyridylsulfide gives upon heating in tetraline and DMF a mixture of 2-methyl-2,3-dihydrothieno[2,3-b]pyridine, dihydrothiopyrano[2,3-b]pyridine, and a mixture of sulfides and disulfides which are formed upon recombination of thiyl radicals. The S-oxide of this sulfide forms only 2-methyl-2,3-dihydrothieno[2,3-b]pyridine of cyclic compounds, which indicates a predominant 2,3- and not 3,3-sigmatropic rearrangement.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 851–853, June, 1989.     

Electrophilic cyclization of o-acetoxy- and o-benzyloxyalkynylpyridines: an easy entry into 2,3-disubstituted furopyridines

[reaction: see text] 2,3-Disubstituted furo[3,2-b]pyridines, 2,3-disubstituted furo[2,3-b]pyridines, and 2,3-disubstituted furo[2,3-c]pyridines are readily prepared under mild conditions via the palladium-catalyzed cross-coupling of 1-alkynes with o-iodoacetoxy- or o-iodobenzyloxypyridines, followed by electrophilic cyclization by I(2) or by PdCl(2) under a balloon of carbon monoxide.     

Functional derivatives of thiophene

A method is proposed for the synthesis of 5-acylamino-2,3-dimethylthiophene-4-carbaldehydes and 5-acylamino-2,3-tetramethylenethiophene-4-carbaldehydes by the formylation of the corresponding thiophenes using the Vilsmeier reaction. From the formyl derivatives obtained, previously unaccessible derivatives of thieno[2,3-b]pyridine, thieno[2,3-d]pyrimidine, and thieno[3′,2′∶5,6]pyrido[2,3-d]-pyrimidine have been synthesized.     

Studies on mesoionic compounds,II. The solvent effect on the electronic absorption spectra of mesoionic 2,3-diaryl-2H-tetrazolium-5-thiolate derivatives

The electronic absorption spectra of 2,3-di(2-fluorophenyl)-, 2,3-di(4-fluorophenyl)-, 2,3-di-(2-chlorophenyl)-, 2,3-di(2-methylphenyl)-, 2,3-di(4-methylphenyl)- and 2,3-di(2-methoxyphenyl)-2H-tetrazolium-5-thiolates have been measured in pure and mixed solvents. They were found to exhibit three characteristic absorption bands at 480-380 nm, near 250 and near 210; the longest wavenlength band of which was assigned to an n → π* transition.     

沸石咪唑酯骨架结构材料ZIF-71用于低浓度生物基2，3-丁二醇/1，3-丙二醇的吸附分离性能

1,3-丙二醇是一种重要的化工原料,生物发酵法生产1,3-丙二醇往往会产生副产物2,3-丁二醇,限制了生物基1,3-丙二醇的进一步工业化应用。1,3-丙二醇与2,3-丁二醇亲水性强,导致其在低浓度发酵液中分离困难。基于2,3-丁二醇比1,3-丙二醇具有长的碳链和大的极化率,本文采用含有―Cl基团（憎水且具有大的极化率）的ZIF-71吸附分离水中低浓度的2,3-丁二醇/1,3-丙二醇。结果表明,ZIF-71对双组分2,3-丁二醇/1,3-丙二醇（50 g/L,50 g/L）中2,3-丁二醇的静态竞争吸附容量为123.6 mg/g,对2,3-丁二醇/1,3-丙二醇分离选择性高达7.6,分离效果优于沸石材料Beta。在3次循环吸附-解吸实验中ZIF-71依旧保持着稳定的结构和对2,3-丁二醇的选择性吸附能力。通过分子模拟,揭示了ZIF-71对1,3-丙二醇和2,3-丁二醇的吸附分离机制。ZIF-71与1,3-丙二醇之间主要通过弱的范德华力作用;而ZIF-71与2,3-丁二醇之间则是通过强的范德华力与弱的氢键协同作用,从而对2,3-丁二醇产生选择性吸附。可以看出, ZIFs材料有望成为选择性吸附分离低浓度副产物2,3-丁二醇的吸附剂,推动生物法制1,3-丙二醇的工业化发展。     

Reduction of 2,3-<Emphasis Type="Italic">Seco</Emphasis>-28-oxo-19<Emphasis Type="Italic">β</Emphasis>,28-epoxy-18<Emphasis Type="Italic">α</Emphasis>-olean-2,3-dicarboxylic acid and its cyclic anhydride

Reduced derivatives of 2,3-seco-28-oxo-19β,28-epoxy-18α-olean-2,3-dicarboxylic acid and its cyclic anhydride were prepared. Reduction of the starting 2,3-secodicarboxylic acid by NaBH₄–I₂ produced the 2,3-seco-2,3-dihydroxy derivative. Reaction of the starting anhydride with LiAlH₄ gave the 2,3-seco2,3,19β,28-tetrahydroxy derivative. Cyclization using acidic reagents of the 2,3-seco-2,3-hydroxy- and 2,3seco-2,3,19β,28-tetrahydroxy derivatives gave the corresponding cyclic ethers containing an oxepane ring. The anhydride ring was reduced by NaBH₄ to the corresponding ε-lactone, the structure of which was confirmed by an x-ray crystal structure.     

Synthesis of 2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine and its 1-α-L-arabinopyranoside

A new type of isatin analog-2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine — was obtained by oxidation of 4-methyl-6-chloro-1H-pyrrolo(2,3-b]pyridine. Condensation of L-arabinose with 4-methyl-6-chloro-2,3-dihydropyrrolo[2,3-b]pyridine and subsequent acetylation and dehydrogenation gave 1-(2,3,4-tri-O-acetyl--L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine, which served as the starting compound for the synthesis of 1--L-arabinopyranosyl-4-methyl-6-chloropyrrolo[2,3-b]pyridine. Oxidation of 1-(2,3,4-tri-O-acetyl-L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine gave 1-(2,3.4-tri-O-acetyl--L-arabinopyranosyl)-2,3-dioxo-2,3-dihydro-4-methyl-6-chloropyrrolo [2,3-b]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1083–1086, August, 1977.     

Transformations of 5-methyl-6-carbethoxy-3,4-dihydrothieno-[2,3-d]pyrimidine for synthesis of 4-methoxy-, 4-alkylamino-, and other derivatives of thieno[2,3-d]pyrimidine

4-Chloro derivatives of thieno[2,3-d]pyrimidine are formed by the action of phosphorus oxychloride on 5-methyl- and 5-methyl-6-carbethoxythieno[2,3-d]pyrimidin-4-ones. Action of nucleophilic reagents (methanol, sodium methylate, primary and secondary amines) on these chloro derivatives gave 4-methoxy-, 4-alkylamino-, and 4-dialkylamino substituted thieno[2,3-d]pyrimidines. It was found that 4-methoxy derivatives of thieno[2,3-d]pyrimidines undergo a thermal rearrangement into 3-methyl-substituted thieno[2,3-d]pyrimid-4-ones. In the bromination of 5-methyl-4-chloro- and 5-methyl-4-methoxy-substituted thieno[2,3-d]pyrimidines by N-bromosuccinimide, 5-bromomethyl derivatives of thieno[2,3-d]pyrimidine are formed, from which, by the action of primary and secondary amines, 5-aminomethyl-substituted thieno[2,3-d]pyrimidines were obtained. A synthesis of 1,2,3,4-tetrahydro-1,3-diazepino[4a,10-d,e] thieno[2,3-d]pyrimidines was also carried out.Deceased.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 7, pp. 925–928, July, 1985.