Studies on new platelet aggregation inhibitors 1. Synthesis of 7-nitro-3,4-dihydroquinoline-2(1H)-one derivatives.

A series of 6-cyclic aliphatic amino-7-nitro-3,4-dihydroquinoline-2(1H)-ones were prepared and tested for platelet aggregation inhibitory effect, cardiotonic activity and chronotropic activity. These compounds appeared to show selective inhibitory activity against platelet aggregation. Among them, 6-(4-ethoxycarbonylpiperidino)-7-nitro-3,4-dihydroquinoline-2(1H)-one (22f) showed the most potent inhibitory activity and high selectivity. A divergent synthetic route to 6-cyclic aliphatic amino-7-nitro-3,4-dihydroquinoline-2(1H)-one derivatives has also been investigated.     

Synthesis of pyrano[3,4-c]pyrazole and pyrazolo[3,4-d][1,2]diazepine derivatives

By the action of thionyl chloride on 3(5)-R-4-phenacylpyrazole-5(3)-carboxylic acid ( 3c,d ), 3-R-5-phenylpyrano[3,4-c]pyrazole-7-(1H)ones ( 4c,d ) were obtained. When 4c,d were treated with hydrazine hydrate followed by refluxing in ethanol containing acetic acid, 4,7-dihydro-3-R-5-phenylpyrazolo[3,4-d][1,2]-diazepin-8-(1H)ones ( 6c,d ) were formed. Compounds 6c,d , in turn, were refluxed in ethanol saturated with hydrochloric acid to yield 6-amino-1,6-dihydro-3-R-5-phenyl-7H-pyrazolo[3,4-c]pyridin-7-ones ( 7c,d ). Compounds 7c,d could be obtained directly from 5c,d. The starting materials 3c,d were prepared by hydrolysis of the oxime of 3(5)-R-4-phenacyl-5(3)carboalcoxypyrazoles ( 1a,b ). Structural assignments rested on correct elemental analysis, molecular weights determined by mass spectrometry, and spectroscopic evidence.     

新型吡咯并三嗪酮类PARP-1抑制剂的设计、合成及生物活性

分别以5-溴-2-氟苯甲腈(1a)和3-溴苯甲腈(1b)为原料,经Sonogashira偶联,脱三甲基硅基保护基,三分子偶联及水解等5步反应制得中间体2-氟-5-［(4-氧代-3,4-二氢吡咯［1,2-d］［1,2,4］三嗪-1-基)甲基］苯甲酸（6a)和3-[(4-氧代-3,4-二氢吡咯［1,2-d］［1,2,4］三嗪-1-基)甲基］苯甲酸（6b）。环烷基甲酸经酰氯化,缩合和脱Boc保护基3步反应制得环烷基哌嗪-1-基甲酮(7a~7c)。 6a与NCS（1 eq.）反应制得5-［(6-氯-4氧代-3,4二氢吡咯［1,2-d］［1,2,4］三嗪-1-基)甲基］-2氟 苯甲酸(6c); 6a与NCS(2 eq.)反应制得5-［(6,7-二氯-4氧代-3,4二氢吡咯［1,2-d］［1,2,4］三嗪-1-基)甲基］-2氟-苯甲酸(6d)。 6a~6d, 6a~6c分别与7a~7c和1-（2-嘧啶基）哌嗪在TBTU（缩合剂）,DIPEA（碱）的作用下合成了13个新型吡咯并三嗪酮类PARP-1抑制剂(8a~8m),其结构经¹HNMR和MS(ESI)表征。采用Alarm blue法研究了8a~8m对肿瘤细胞MDA-MB-436的抑制活性(IC₅₀)。结果表明：8f, 8g, 8i和8j对MDA-MB-436有较强的抑制活性（IC₅₀=30.5~69.3 nmol·L^-1）。     

Palladium-catalyzed heteroannulation leading to heterocyclic structures with two heteroatoms: a highly regio- and stereoselective synthesis of (Z)-4-alkyl-2-alkyl(aryl)idene-3,4-dihydro-2H-1,4-benzoxazines and (Z)-3-alkyl(aryl)idene-4-tosyl-3,4-dihydro-2H-1,4-benzoxazines.

A highly convenient method has been developed for the synthesis of (Z)-4-alkyl-2-alkyl(aryl)idene-3,4-dihydro-2H-1,4-benzoxazines 9 and (Z)-3-alkyl(aryl)idene-4-tosyl-3,4-dihydro-2H-1,4-benzoxazines 34-38 through palladium-copper-catalyzed reactions. Aryl halides 7 reacted with 2-[N-alkyl(benzyl)-N-prop-2'-ynyl]aminophenyl tosylate 6 in the presence of (PPh3)2PdCl2 (3 mol %), CuI(5 mol %) in triethylamine at room temperature to yield 2-[N-alkyl(benzyl)-N-(3-aryl-prop-2'-ynyl)]-aminophenyl tosylates 8 in extremely good yields (72-96%). The latter could then be cyclized with KOH in ethanol-water to Z-9 in a highly regio- and stereoselective manner. Similarly, palladium-copper-catalyzed reaction of 2-(prop-2'-ynyloxy)aniline (21) with aryl iodides 7 led to 22-26 which after tosylation and cyclization with cuprous iodide in CH3CN in the presence of K2CO3 and Bu4-NBr led to the (Z)-3-alkyl(aryl)idene-4-tosyl 3,4-dihydro-2H-1,4-benzoxazines 34-38 in good overall yields. The Z-stereochemistry of the products was established from 1H NMR spectra, 3JCH values (between vinylic proton and methylenic carbon of the heterocyclic ring), NOE experiments, and X-ray analysis. The method was also found to be suitable for the synthesis of bis(benzoxazinylated) derivatives 17, 39, and 2-alkyl-3,4-dihydro-2H-1,4-benzoxazines 18. Our method for the synthesis of 3,4-dihydro-2H-1,4-benzoxazines is highly efficacious, using easily available starting materials under very mild conditions. Also the synthesis of some novel 5-substituted uracil derivatives 40 and 41 containing the benzoxazinyl moiety and of potential biological interest is being reported.     

含吲哚的吡唑并[3,4-d]嘧啶衍生物的设计合成及其生物活性研究

利用药物设计中的生物活性基团拼接原理,设计合成了13个含吲哚的吡唑并[3,4-d]嘧啶衍生物.目标化合物均经核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)和高分辨质谱仪(HRMS)进行了结构确证.对4株肿瘤细胞(HeLa、MGC-803、MCF-7、BEL-7404)的体外抗增殖活性实验结果表明,目标化合物均表现出一定的抗肿瘤活性,MCF-7、MGC-803肿瘤细胞株敏感度高于HeLa和BEL-7404.其中, 6-[(6-甲氧羰基吲哚-3-基)硫基]-1-苯基-吡唑并[3,4-d]嘧啶-4-酮(5m)表现出较好的体外肿瘤抑制活性,对MCF-7、MGC-80和HeLa细胞的IC50均小于30μmol·L^-1,对MCF-7的IC50值为(4.02±0.92)μmol·L^-1,优于对照药物依托泊苷(10.1±0.62μmol·L^-1)和羟喜树碱(5.93±0.56μmol·L^-1).拓扑异构酶抑制实验结果表明,此类化合物对TopoII有选择性抑制活性,所有化合物对TopoⅡ表现出不同程度抑制活性,对Topo Ⅰ未表现出抑制活性.     

A convenient synthesis of 5‐alkylthio‐3,4‐diarylisoxazoles by palladium‐catalyzed coupling reactions

Palladium‐catalyzed coupling reaction was found effective for rapid access to pharmacologically interesting 3,4‐diarylisoxazoles derivatives as selective COX‐2 inhibitors. Thus, the coupling reaction between 5‐alkylthio‐3‐aryl‐4‐iodoisoxazoles and arylboronic acids afforded the target 5‐alkylthio‐3,4‐diarylisoxazoles in good yields.     

C,O-dialkylation of Meldrum's acid: synthesis and reactivity of 1,3,7,7-tetramethyl-4H,10H-6,8,9-trioxa-2-thiabenz[f]azulen-5-one

Reaction of Meldrum's acid with 3,4-bis(chloromethyl)-2,5-dimethylthiophene (1) or 3,4-bis(bromomethyl)-2,5-dimethylthiophene (2) produces the kinetically favored C,O-dialkylation product, 1,3,7,7-tetramethyl-4H,10H-6,8,9-trioxa-2-thiabenz[f]azulen-5-one (4). Recrystallization of 4 from refluxing methanol results in the methanolysis product 5-(4-methoxymethyl-2,5-dimethylthiophen-3-ylmethyl)-2,2-dimethyl[1,3]dioxane-4,6-dione (5). Attempts to isomerize 4 to the thermodynamically favored C,C-dialkylation product, 1,3-dimethyl-5,6-dihydro-4H-cyclopenta[c]thiophene(2-spiro-5)2,2-dimethyl-4,6-dione (8), result in the formation of 1,3-dimethyl-7,8-dihydro-4H-thieno[3,4-c]oxepin-6-one (6). The transformation occurs via a retro-Diels-Alder elimination of acetone followed by hydrolysis and decarboxylation of the resulting ketene. The ketene is trapped by tert-butyl alcohol, furnishing 1,3-dimethyl-6-oxo-7,8-dihydro-4H,6H-thieno[3,4-c]oxepine-7-carboxylic acid tert-butyl ester (7). All compounds are characterized spectroscopically as well as by X-ray crystallography of products 4-7.     

Reactions of Diferrocenylmorpholino- and -Methylsulfanyl-cyclopropenylium Salts with β-Dicarbonyl Compounds and Diethyl Malonate

2,3-Diferrocenyl-1-morpholinocyclopropenylium tetrafluoroborate reacts with ethyl acetoacetate, ethyl benzoylacetate, and diethyl malonate in the presence of triethylamine to yield 3-[acyl(ethoxycarbonyl)]-, 3-(diethoxycarbonyl)-methyl-3-morpholino-1,2-diferrocenylcyclopropenes (3a–c), and 3-[acyl(ethoxycarbonyl)]- and (diethoxycarbonyl)-methylidene-1,2-diferrocenylcyclopropenes (4a–c) in a ca. 1:1.5 ratio. 2,3-Diferrocenyl-1-methylsulfanylcyclopropenylium iodide with the same substrates affords compounds 4a,b (～10–15%), 3-[acyl(ethoxycarbonyl)]methyl-3-methylsulfanyl-1,2-diferrocenylcyclopropenes (5a,b) (～8–10%), 2-acyl-3,4-diferrocenyl-5-methylsulfanylcyclopentadienones (6a,b), ethyl 2-acyl-3,4-diferrocenyl-5-methylsulfanylpenta-2,4-dienoates (7a,b; 8a,b), and ethyl 3,4-diferrocenyl-2-methylsulfanyl-6-oxohexa(hepta)-2,4-dienoates (9a,b). The spatial structure of ethyl Z,E-3,4-diferrocenyl-2-methylsulfanyl-6-oxohepta-2,4-dienoate (9b) was established based on the data from x-ray diffraction analysis. Electrochemical properties of 3-[acyl(ethoxycarbonyl)]- and (diethoxycarbonyl)-methylidene-1,2-diferrocenylcyclopropenes (4a–c) are studied.     

Synthesis of novel isoxazole functionalized pyrazolo[3,4-b]pyridine derivatives; their anticancer activity

A series of novel isoxazole functionalized pyrazolo[3,4-b]pyridine derivatives 5a-n were prepared, respectively, initiated from 6-thiophenyl-4-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-3-amine 3 through selective N-propargylation, and these N-propargylated compounds 4 were cyclized with aryloximes by using of sodium hypochlorite, and obtained the title products 5a-n . All the final products 5a-n were submitted for anticancer activity against four cancer cell lines such as “HeLa—cervical cancer (CCL-2); COLO 205—colon cancer (CCL-222); HepG2—liver cancer (HB-8065); MCF7—breast cancer (HTB-22)”; Compounds 5c , 5d , and 5h are found to have more prominent anticancer activity at micro molar concentration.     

New insights into the acid-promoted reaction of caffeic acid and its esters with nitrite: decarboxylation drives chain nitrosation pathways toward novel oxime derivatives and oxidation/fragmentation products thereof

In 0.05 M acetate buffer, pH 4, containing 1% methanol, caffeic acid (1a) (2 x 10(-3) M) reacted smoothly with nitrite (NO(2)(-)) (4 x 10(-3) M) to afford as main products the novel 2-hydroxy- and 2-methoxyaldoximes 7a,b, the 2-oxoaldoxime 9a, 3,4-dihydroxybenzoic acid, 3,4-dihydroxybenzaldehyde, and the known furoxan 3c and benzoxazinone 4b in smaller amounts. At lower 1a concentration (e.g., 1 x 10(-4) M), 7a was the main product, whereas with 0.1 M 1a and 0.5 M NO(2)(-) 3c and 9a were prevailing. At pH 2, 7a was still the most abundant product, together with 3,4-dihydroxybenzaldehyde and some 9a, whereas at pH 1 9a and 3,4-dihydroxybenzaldehyde were formed in higher yields. No evidence for ring nitration products, including the previously reported 4,5-dihydroxy-2-nitrobenzaldehyde, was obtained. At 2 x 10(-3) M concentration and at pH 4, caffeic acid methyl ester (1b) reacted with NO(2)(-) chiefly via ring nitration and/or dimerization to give 5a, the novel nitrated neolignan derivative 10, and the parent 6. Chlorogenic acid (1c) afforded only the ring nitrated derivative 5b. A unifying mechanism for the reaction of 1a and its esters with NO(2)(-) is proposed involving reversible formation of nitroso intermediates via chain nitrosation at the 2-position of the (E)-3-(3,4-dihydroxyphenyl)propenoic system. In the case of 1a, decarboxylation would drive the nitroso intermediates toward the formation of oximes 7a,b and 3c, reflecting nucleophilic addition of water, methanol, and NO(2)(-), and their oxidation or breakdown products, viz. 9a, 3,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, and the benzoxazinone 4b. In the case of esters 1b,c, to which decarboxylation is precluded, ring nitration or dimerization become the favored routes, triggered by preliminary oxidation at the catechol moiety.     

Condensation of 2-naphthol and naphthalenediols with o-dichlorobenzene in the presence of aluminum halides

It is known that 1-naphthol, as a result of superelectrophilic (dicationic) activation in superacid media, is able to react with such deactivated aromatic compound as o-dichlorobenzene to give 4-(3,4-dichlorophenyl)-1-tetralone (2), which is a highly valuable intermediate in the synthesis of the antidepressant, sertraline (1) and other useful derivatives. However, the analogous reactivity of 2-naphthol and a variety of naphthalenediols towards o-dichlorobenzene has not been investigated thus far, although the corresponding tetralones, bearing dichlorophenyl moiety, could be of great pharmacochemical interest. In present work, we disclose that 1,5-, 1,6-, and 1,7- naphthalenediols (6a-c) react smoothly with o-dichlorobenzene in the presence of an excess of aluminum chloride or aluminum bromide to give the pairs of isomeric 4-(3,4-dichlorophenyl)- and 4-(2,3-dichlorophenyl)- 5-, 6-, and 7-hydroxy-1-tetralones (10a-c and 11a-c) in high overall yields. 2-Naphthol and 2,7-naphthalenediol (6d) exhibited comparatively lower reactivity, which however was sufficient to obtain the corresponding dichlorophenyl-2-tetralones in moderate yields. The mechanism of these reactions involving superelectrophilic dicationic or even tricationic intermediates, is discussed.     

Polyphenyl macrocyclic oligophenylenes

The Diels-Alder reaction of tribenzohexadehydro[12]annulene (12) and 3,4-diphenyl-2,5-dimethylcyclopentadienone (13) at 300 degrees C gave the triple adduct 2,3,10,11,18,19-hexaphenyl-1,4,9,12,17,20-hexamethylhexa-o-phenylene (6b) in 13% yield. NMR and X-ray analysis indicated that 6b adopts a screw conformation (C2) rather than a crown conformation (C3), and computational studies seem to rule out any interconversion of the two. Palladium-catalyzed coupling of 1,2-bis(4-bromophenyl)-3,4,5,6-tetraphenylbenzene (17) and the corresponding bis(boronic acid) 18 gave a mixture of linear and cyclic oligomers of hexaphenylbenzene containing two to six hexaphenylbenzene subunits. A macrocyclic tetramer was isolated from this mixture in 5% yield, and X-ray analysis showed it to be the "supertetraphenylene" 7 (C168H112) that contains a large central cavity and packs to form highly solvated, porous crystals. The difficulties encountered in the purification of 7 led to the development of alternative, more highly selective syntheses that give the pure macrocycle more easily but in essentially the same overall yield.     

A stereoselective synthesis of tri-substituted alkenes. The nickel-catalysed coupling of Grignard reagents with 6-alkyl-3,4-dihydro-2H-pyrans.

The nickel-catalysed coupling of certain Grignard reagents with 6-alkyl-3,4-dihydro-2H-pyrans is highly stereoselective and gives tri-substituted alkenes with retention of configuration. The method was applied to the synthesis of (E)-3-Acetoxy-7-methyl-6-nonene, the aggregation phermone of the square-necked grain beetle.     

Synthesis of 2-oxohexahydrothieno[3,4-d]imidazole derivatives

Conclusions We synthesized the cis-3- and 4-methyl-2-oxo-6-(-carboxybutyl) hexahydro [3,4-d]-imidazoles by the reduction of the 3- and 4-methyl-2-oxo-2,3-dihydro-6-(carboxybutyl)-1H-thieno [3,4-d] imidazoles with HSiEt₃ in CF₃COOH and subsequent alkaline hydrolysis of the intermediate methyl ethers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1634–1636, July, 1980.The authors express their gratitude to Prof. A. Mark (France) for supplying the sample of 2-oxo-4-methyl-6-(6-carboxybutyl)hexahydrothieno[3,4-d]imidazole.     

Development of Nanodomain and Fractal Morphologies in Solvent Annealed Block Copolymer Thin Films

We have systematically studied the thin film morphologies of asymmetric polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) diblock copolymer subjected to solvent vapors of varying selectivity for the constituent blocks. Upon a short treatment in neutral or PS‐selective vapor, the film exhibited a highly ordered array of hexagonally packed, cylindrical microdomains. In the case of PEO selective vapor annealing, such ordered cylindrical microdomains were not obtained. Instead, fractal patterns on the microscale were observed and their growth processes investigated. Furthermore, hierarchical structures could be obtained if the fractal pattern was exposed to neutral or PS selective vapor.

     

Proton sponge phosphines: electrospray-active ligands

Attachment of a proton sponge to a phosphine ligand renders neutral complexes of the ligand highly amenable to analysis by electrospray ionisation mass spectrometry (ESI-MS). The ligand 1,8-bis(dimethylamino)naphthyldiphenylphosphine (3) is extremely efficient and highly selective in forming exclusively [M + H]+ ions, which may be detected at very low concentration. Ionisation efficiency of 3 in the presence of H+ approached 100%. The bis-substituted ligand bis{1,8-bis(dimethylamino)naphthyl}phenylphosphine (4) was also prepared and characterised, as were Fe(CO)4- (5c), Mn(eta5-C5H4Me)(CO)2- (6) and W(CO)5- (7) complexes of 3. Compounds 3, 3.HBr.EtOH, 4 and 5c were all structurally characterised.     

Interaction of 1,2,5-chalcogenadiazole derivatives with thiophenolate: hypercoordination with formation of interchalcogen bond versus reduction to radical anion

According to the DFT calculations, [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (4), [1,2,5]selenadiazolo[3,4-c][1,2,5]thiadiazole (5), 3,4-dicyano-1,2,5-thiadiazole (6), and 3,4-dicyano-1,2,5-selenadiazole (7) have nearly the same positive electron affinity (EA). Under the CV conditions they readily produce long-lived π-delocalized radical anions (π-RAs) characterized by EPR. Whereas 4 and 5 were chemically reduced into the π-RAs with thiophenolate (PhS(-)), 6 did not react and 7 formed a product of hypercoordination at the Se center (9) isolated in the form of the thermally stable salt [K(18-crown-6)][9] (10). The latter type of reactivity has never been observed previously for any 1,2,5-chalcogenadiazole derivatives. The X-ray structure of salt 10 revealed that the Se-S distance in the anion 9 (2.722 ?) is ca. 0.5 ? longer than the sum of the covalent radii of these atoms but ca. 1 ? shorter than the sum of their van der Waals radii. According to the QTAIM and NBO analysis, the Se-S bond in 9 can be considered a donor-acceptor bond whose formation leads to transfer of ca. 40% of negative charge from PhS(-) onto the heterocycle. For various PhS(-)/1,2,5-chalcogenadiazole reaction systems, thermodynamics and kinetics were theoretically studied to rationalize the interchalcogen hypercoordination vs reduction to π-RA dichotomy. It is predicted that interaction between PhS(-) and 3,4-dicyano-1,2,5-telluradiazole (12), whose EA slightly exceeds that of 6 and 7, will lead to hypercoordinate anion (17) with the interchalcogen Te-S bond being stronger than the Se-S bond observed in anion 9.     

Modified Coumarins. 17. Synthesis and Anticoagulant Activity of 3,4-Cycloannelated Coumarin D-Glycopyranosides

3,4-Cyclocondensed coumarin O-glycopyranosides containing glucose, galactose, xylose, and arabinose were synthesized by condensation of potassium salts of hydroxycoumarins and acetobromosugars. 7-(β-D-Galactopyranosyloxy)-2,3-dihydrocyclopenta[c]chromen-4-one, 3-(β-D-xylopyranosyloxy)-7,8,9,10-tetrahydrobenzo[c]chromen-6-one, and 3-(α-D-arabinopyranosyloxy)benzo[c]chromen-6-one exhibited distinct anticoagulant activity. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 416–419, September–October, 2005.     

Synthesis of 3,3′-(1,6-hexanediyl)bis-pyrimidine derivatives and 3,4-dithia[6.6](1.3)pyrimidinophane

Several 3,3′-(1,6-hexanediyl)bis[6-methyl-2,4(1H,3H)-pyrimidinedione] derivatives ( 4a, 4b , and 4c ) were synthesized from 1,6-(hexanediyl)bis[6-methyl-2H-1,3-oxazine-2,4(3H)-dione] (3) . Compound 4c was converted to 6, which reacted with thiourea giving thiuronium salt 7 . 3,3′-(1,6-Hexanediyl)bis [1-(2-mercaptoethyl)-6-methyl-2,4(1H,3H)-pyrimidinedione] (9) was obtained by the hydrolysis of 7 , and then 9 was oxidized to 12,22-dimethyl-3,4-dithia[6.6] (1.3)-1,2,3,4-tetrahydro-2,4-dioxopyrimidinophane (10) .     

Synthesis of substituted 5H-pyradazino [3,4-b]-1,4-benzoxazine (3,4-diazaphenoxazine)

10-Methyl-2-chloro- and 2-chloro-3-methyl-3,4-diazaphenoxazines as well as 2-oxo-3,10-dimethyl-2,3-dihydro-3, 4-diazaphenoxazine were obtained by methylation of 2-chloro-3,4-diazaphenoxazines. Depending on the conditions, alkylation of 2-chloro-3,4-diazaphenoxazine with -diethylaminoethyl chloride gave 1-ethylimidazolino[1,21,2]pyridazo[3,4-b]-1,4-benzoxazine or 2-ethoxy-10-(-diethylaminoethyl)-3,4-diazaphenoxazine. A number of 10-alkyl- and 10-dialkylaminoalkyl-2-chloro-3,4-diazaphenoxazines were obtained by condensation of 3,4,6-trichloropyridazine with substituted o-aminophenols.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 750–754, June, 1971.