Unsaturated acids containing trifluoromethyl groups

Summary The addition of water, ammonia, and piperidine to 3,3-bistrifluoromethylacrylic acid and its ester was carried out and led to the formation of 2-substituted 3,3-bistrifluoromethylpropionic acids. This indicates that the polarization of the double bond in 3,3-bistrifluoromethylacrylic acid is in the reverse direction to that in trifluorocrotonic acid.     

Alpha-glucosidase inhibitors ellagic acid derivatives with immunoinhibitory properties from Terminalia superba

Fractionation of stem barks of Terminalia superba yielded two new ellagic acid derivatives, 3,4'-di-O-methylellagic acid 3'-O-beta-D-xylopyranoside (1) and 4'-O-galloy-3,3'-di-O-methylellagic acid 4-O-beta-D-xylopyranoside (2) together with known 3,3'-di-O-methylellagic acid, ellagic acid and 3,3'-di-O-methylellagic acid 4'-O-beta-D-xylopyranoside. Compounds (1) and (2) showed significant alpha-glucosidase inhibition activity and possessed significant immunoinhibitory activities with no cytotoxic effects.     

Thermally stable polymers from 1,4,5-naphthalene–tricarboxylic acid and aromatic tetramines

New thermally stable polymers that contained benzimidazole and benzimidazobenzoisoquinoline fragments in polymer chains were synthesized by one-stage cyclopolycondensation of aromatic tetramines (3,3′, 4,4′-tetraminodiphenyl ether, 3,3′,4,4′-tetraminodiphenyl methane, 3,3′,4,4′-tetraminodiphenyl sylfone, and 3,3′-diaminobenzidine) with 1,4,5-naphthalene tricarboxylic acid 4:5–anhydride in polyphosphoric acid and with 1,4,5-naphthalene tricarboxylic acid 4:5–anhydride 1-phenyl ester. All polymers obtained were soluble in concentrated sulfuric acid, 85% phosphoric acid, polyphosphoric acid, methane sylfonic acid. Some were soluble in formic acid. Thermogravimetric analyses indicated that these polymers were stable up to 450–500°C in air. The polymers had good hydrolytic stability.     

Studies on the metabolism of 4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3- diphenylpropyl ester hydrochloride in rat bile by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry

4-Methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208) is a newly synthesized compound which has shown excellent in vivo and in vitro anticancer activity and low toxicity. In the present study, the major metabolites of TM208 in rat bile were studied by high-performance liquid chromatography/tandem mass spectrometry with an electrospray ionization (ESI) interface. It was demonstrated that TM208 was extensively metabolized in rat bile and nine metabolites (M1-M9) were definitely or tentatively identified: (2-aminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M1), (2-methylaminoethyl)dithiocarbamic acid 3-cyano-3,3-diphenylpropyl ester (M2), 4-[(4-methylpiperazin-1-yl)thioxomethanesulfinyl]-2,2-diphenylbutyronitrile (M3), 4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester(M4), the sulfine of (4-methylpiperazine-1-carbodithioc acid 3-cyano-3,3-diphenylpropyl ester) (M5), 4-methylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M6), piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester (M7), 4-hydroxymethylpiperazine-1-carbothioic acid S-(3-cyano-3,3-diphenylpropyl) ester (M8) and the sulfine of [4-methylpiperazine-1-carbodithioic acid 3-cyano-3-(4-hydroxyphenyl)-3-phenylpropyl ester] (M9).     

Chemical constituents with antibacterial activity from Euphorbia sororia

A group of ceramide (1) was isolated from the aerial parts of Euphorbia sororia. On the basis of spectroscopic data, chemical methods and GC-MS analysis, the structure of 1 was characterised as (2S,3S,4R,8E)-2-(eicosanoyl approximately octacosanoyl amino)-1,3,4-octadecanetriol-8-ene. In addition, four known ellagic acid derivatives 3,3'-di-O-methylellagic acid (2), 3,3',4'-tri-O-methylellagic acid (3), 4-O-sulfooxy-3,3'-di-O-methylellagic acid (4) and 4-O-sulfooxy- 3,3',4'-tri-O-methylellagic acid (5) were isolated from the plant. Biological screening of all compounds revealed moderate antibacterial activity.     

Synthesis of new 3,3-dimethoxyazetidine-2-carboxylic acid derivatives

Cyclization of γ-amino-α-bromocarboxylic esters resulted in an efficient synthesis of new 3,3-dimethoxyazetidine-2-carboxylates, that is, methyl N-t-butyl-3,3-dimethoxyazetidine-2-carboxylic ester and 3,3-dimethoxyazetidine-2-carboxylic acid, or 3-bromo-4,4-dimethoxypyrrolidin-2-ones, depending on the substituent at nitrogen. Reduction of the 3,3-dimethoxyazetidine-2-carboxylates gave the corresponding 3,3-dimethoxy-2-(hydroxymethyl)azetidines. These novel cyclic amino acid derivatives, available on multigram scale, have a suitably protected carbonyl function at the 3-position, which enables further functionalization.     

Analysis of 4-methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenyl-propyl ester hydrochloride and its major metabolites in rat plasma and tissues by LC-MS/MS

4-Methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM-208) is a newly synthesized compound, which has shown excellent in vivo and in vitro anticancer activity and low toxicity. To investigate the metabolism of TM-208 in rats, in the present study, we administered TM-208 orally to rats and analyzed its metabolites existing in rat plasma and central tissues by LC-MS/MS. Rat plasma and tissue samples were collected before or after a single oral dose (250 mg/kg) of TM-208, then the analytes were extracted from samples by liquid-liquid extraction and analyzed using LC-MS/MS. The structures of proposed metabolites were elucidated according to the rules of drug metabolism and disposition in vivo and the characteristic fragmentation behaviors of TM-208 in ESI-ITMS(n). Five metabolites (M1-M5) were tentatively or assuredly identified: (2-amino-ethyl)-dithiocarbamic acid 3-cyano-3,3-diphenyl-propyl ester (M1), (2-methylamino-ethyl)-dithiocarbamic acid 3-cyano-3,3-diphenyl-propyl ester (M2), 4-methyl-piperazine-1-carbothioic acid S-(3-cyano-3,3-diphenyl-propyl) ester (M3), piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester (M4), and sulfine of (4-methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester) (M5).     

Analogs of D(+)-pantothenic acid. VI. Synthesis of D-, L-, and DL-4′-amino-4′-deoxypantothenic acid

A new analog of pantothenic acid, DL-4-amino-2-hydroxy-3,3-dimethylbutanoic acid, has been synthesized and it has been separated into stereoisomer. D-, L-, and DL-N-(4-Amino-2-hydroxy-3,3-dimethylbutyryl)-β-alanines — amino analogs of pantothenic acid — have been synthesized by the condensation of the N-hydroxysuccinimide esters of N-BOC-D-, -L-, and -DL-4-amino-2-hydroxy-3,3-dimethylbutanoic acids with β-alanine, followed by the elimination of the protective groups.     

Effects of structure on properties of some new aromatic-aliphatic polybenzimidazoles

Polybenzimidazoles were prepared in poly(phosphoric acid) from isophthalic, m- and p-phenylene diacetic, succinic, adipic, suberic, and sebacic acids and 3,3′-diaminobenzidine, 3,3′,4,4′-tetraaminodiphenyl ether and 3,3′,4,4′-tetraaminodiphenylmethane. The thermal, mechanical, and bonding properties were studied. A 3:1 copolymer of isophthalic and m-phenylenediacetic acid with 3,3′-diaminobenzidine showed the best results as far as isothermal oxidation resistance and thermal and processing characteristics.     

Cyclisation of benzils

Treatment of several substituted benzils [3,3′- and 4,4′-dimethyl-; 2,2′-, 3,3′- and 4,4′-dichloro-; 3,3′-dibromo-; 4-(N,N-dimethylamino)-] with an excess of chlorosulfonic acid gave the corresponding 3-chloro-2-phenylbenzofuran disulfonyl dichlorides. Disubstitution was confirmed by microanalytical and spectral data for the corresponding bis(N,N-dimethylaminsulfonamides). The positions of electrophilic substitution were not confirmed with 3,3′-dimethyl-, 2,2′- and 3,3′-dichlorobenzils. With 4,4′-dichlorobenzil, a smaller amount of chlorosulfonic acid enabled the isolation of 3,6,4′-trichloro-2-phenylbenzofuran-5-sulfonyl chloride, which was identified by X-ray analysis of the N,N-dimethylsulfonamide. The cyclisation failed with 3,3′-dimethoxy-, and 3,3′- and 4,4′-dinitrobenzils. The results have been interpreted mechanistically.     

Self-condensation reaction of aromatic tetraamines in polyphosphoric acid

Ladder and partial ladder polymers have been obtained by self-condensation reactions of 1,2,4,5-tetraaminobenzene, 3,3′,4,4′-tetraaminodiphenyl ether, 3,3′-diaminobenzidine and 3,3′,4,4′-tetraaminodiphenyl sulfone in polyphosphoric acid. The products thus obtained are highly colored compounds with good thermal stability. They seem to be made up of polyquinoxaline or dihydrophenazine or a mixture of these two recurring units. They are slightly soluble in methanesulfonic acid and concentrated sulfuric acid and have inherent viscosities in the 0.2 to 0.4 range.     

Calorimetric and computational thermochemical study of 3,3-tetramethyleneglutaric acid, 3,3-tetramethyleneglutaric anhydride, and 3,3-tetramethyleneglutarimide

The standard (p(o) = 0.1 MPa) molar energies of combustion in oxygen, at T = 298.15 K, of solid 3,3-tetramethyleneglutaric acid and the related 3,3-tetramethyleneglutaric anhydride and 3,3-tetramethyleneglutarimide were measured by static bomb combustion calorimetry. The values of the standard molar enthalpies of sublimation, at T = 298.15 K, were obtained by Calvet microcalorimetry, allowing the calculation of the standard molar enthalpies of formation of the compounds, in the gaseous state, at T = 298.15 K. The geometries of the experimentally studied compounds were fully optimized using density functional theory with the B3LYP functional and extended basis sets. More accurate energies were also obtained from single-point calculations at the most stable B3LYP/6-311G** geometries, using the cc-pVTZ basis set. From these calculations the standard molar enthalpies of formation of 3,3-tetramethyleneglutaric acid, 3,3-tetramethyleneglutaric anhydride, and 3,3-tetramethyleneglutarimide were estimated using isodesmic reactions involving glutaric acid, glutaric anhydride, and glutarimide, respectively. Experimental and computational results were used in the discussion of the interrelation of energetics and structure in these compounds and compared with other structurally related compounds.     

New Reagents for the Reductive Quenching of Ozonolysis Reactions

3,3′-Thiodipropionic acid and its salts were found to be effective reductive quench reagents in the ozonolysis of olefins. They were as effective as methyl sulfide without its drawbacks. A polymer-bound form of 3,3′-thiodipropionic acid was also effective.     

合成(±)顺式-3-(二氯乙烯基)-2,2-二甲基环丙烷羧酸的新方法

本文报道两种从5-氯-3,3-二甲基戊酸乙酯(4)合成±)-顺式-3-(二氯乙烯基)-2,2-二甲基环丙烷羟酸(±)的方法.中间体4,4-二甲基-3,4-二氢-2-吡喃酮(3)是从化合物(4)经水解皂化,酸化和氧得到3,3-二甲基戊醛酸甲酯(6),再皂化得到3,3-二甲基戊醛酸(8),然后环化得到;或者由化合物4经苯基硫醚化,氧化得到8,然后环化后得到.     

Synthesis of 3,3-dinitroazetidine from 1-t-butyl-3,3-dinitroazetidine

Treatment of 1-t-butyl-3,3-dinitroazetidine (1) with benzyl chloroformate resulted in a novel elimination of isobutylene to yield equimolar amounts of 1-(benzyloxycarbonyl)-3,3-dinitroazetidine (3) and 1-t-butyl-3,3-dinitroazetidine hydrochloride. The carbamate 3 was effectively cleaved by trifluoromethanesulfonic acid to yield 3,3-dinitroazetidinium trifluoromethanesulfonate (4) . Free 3,3-dinitroazetidine (5) has also been isolated.     

Reactions of enamino keto esters of 1,2,3,4-tetrahydroisoquinoline series with nucleophiles

It has been shown that the reaction of the methyl ester of 3-(3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-idene)pyruvic acid with thiosemicarbazide in glacial acetic acid leads to heterocyclization with the formation of 3,3-dimethyl-1-(5-thioxo-1,5-dihydro-1,2,4-triazol-3-ylmethylidenecarbonyl)-1,2,3,4-tetra-hydroisoquinoline, but the interaction with semicarbazide under the same conditions leads to annelation of the pyrrole ring. On condensation of the enamino keto ester with malonodinitrile, the nitrile of 2-cyano-4-dicyanomethylidene-5-(3,3-dimethyl-1,2,3.4-tetrahydroisoquinolin-1-idene)-3-oxo-pentanoic acid is formed.     

内型2—（3,3—二甲基—2—降冰片基）丁醛及其衍生物的合成

以内型３，３－二甲基－２－降冰片基乙醛（１）与叔丁胺反应制得醛亚胺（２），依次和溴化乙基镁，碘乙烷反应制得内型２－（３，３－二甲基－２－降冰片基）丁醛的亚胺（４），再经水解得内型２－（３，３－二甲基－２－降冰片基）丁醛（５）。后者经与乙二醇缩醛化及氧化分别制得该醛的缩醛（６）及羧酸（７）。这些化合物均为新化合物，经纯化后进行了结构分析，并对其质谱进行了讨论。     

Polymers with quinoxaline units. III. Polymers with quinoxaline and thiazine recurring units

Six ladder or partly ladder polymers have been prepared by the condensation reactions of combinations of two diaminodithiophenols, 4,6-diamino-1,3-dithiophenol and 3,3′-dimercaptobenzidine, with three tetrachloroquinoxaline derivatives, 2,3,7,8-tetrachloro-1,4,6,9-tetraazaanthracene, 2,2′,3,3′-tetrachloro-6,6′-bisquinoxaline, and 2,2′,3,3′-tetrachloro-6,6′-diquinoxalyl ether, with the use of dimethylacetamide, hexamethylphos phoramide, and polyphosphoric acid as reaction media. The polymers thus obtained are highly colored, powedery materials which are slightly soluble in methanesulfonic acid and concentrated sulfuric acid. These polymers (η_inh > 1) show good thermal stability.     

New entries toward 3,3-difluoropiperidines

Difluoropiperidines attract considerable interest from organic and medicinal chemists, but their synthesis is often problematic. This paper describes a new synthetic pathway toward valuable 3,3-difluoropiperidines starting from suitable delta-chloro-alpha,alpha-difluoroimines. The latter imines can be synthesized via electrophilic fluorination of the corresponding delta-chloroimines using NFSI (N-fluorodibenzenesulfonimide) in acetonitrile. After hydride reduction of the imino bond and subsequent intramolecular substitution of the chloride atom, new 3,3-difluoropiperidines were obtained in good yields. In addition, this methodology was applied to establish the first synthesis of N-protected 3,3-difluoropipecolic acid, a new fluorinated amino acid.     

共吸附剂修饰TiO2薄膜电极

共吸附剂修饰纳晶TiO₂薄膜电极是目前染料敏化太阳电池研究的一个热点. 本文通过平带电势和电化学阻抗研究了二(3,3-二甲基丁基)次膦酸和鹅脱氧胆酸两种共吸附剂修饰对TiO₂薄膜电极的平带电势和电极表面钝化能力的影响及其在染料敏化太阳电池中的应用. 结果表明, 二(3,3-二甲基丁基)次膦酸能更有效地钝化TiO₂薄膜表面, 并使TiO₂薄膜平带电势负移. 电化学阻抗谱测试结果表明, 在染料敏化太阳电池中, 相对于鹅脱氧胆酸, 二(3,3-二甲基丁基)次膦酸能更显著地提高器件的电子寿命和开路电压.