Skeletal transformations of perfluoro-1-ethyl-1-phenylbenzocyclobutene in the reaction with antimony pentafluoride

Interaction of perfluoro-1-ethyl-1-phenylbenzocyclobutene with SbF₅ at room temperature gives, after treatment of the reaction mixture with H₂O, perfluoro-4-[1-(2-methylphenyl)propylidene]cyclohexa-2,5-dienone as a main product. The reaction at 90-95 °C leads, after treatment with H₂O, to a mixture of perfluorinated 9-ethyl-9-methyl-1,2,3,4-tetrahydro-9H-fluorene, 9-ethyl-4a-methyl-4,4a-dihydrofluoren-1-one, 3-ethyl-3-phenylphthalide, 1-hydroxy-2-methyl-1-phenylindan, 3-methyl-2-phenylindenone and small amounts of other products.     

Synthesis and study of 2-(1-pyrazolyl)pyrimidine derivatives

Alkyl derivatives of 2-(1-pyrazolyl)-4(3H)-pyrimidinone were synthesized and converted to 4-chloro-, 4-arylamino-, and 4-hydrazino-2-(1-pyrazolyl)pyrimidines. The corresponding hydrazones were obtained by reaction of 5-ethyl-2-hydrazino-6-methyl-2-(4-ethyl-3,5-di-n-propylpyrazolyl) pyrimidine with isatin and salicylaldehyde. The UV and IR spectra of the synthesized compounds were studied. It was established that the hydrazones contain intra-molecular hydrogen bonds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1257, September, 1977.     

New 7-substituted quinolone antibacterial agents. The synthesis of 1-ethyl-1,4-dihydro-4-oxo-7-(2-thiazolyl and 4-thiazolyl)-3-quinolinecarboxylic acids

A series of 1-ethyl-1,4-dihydro-4-oxo-7-(4-thiazolyl)-3-quinolinecarboxylic acids and 1-ethyl-1,4-dihydro-4-oxo-7-(2-thiazolyl)-3-quinolinecarboxylic acids were prepared. Also prepared was 10-[2-(aminomethyl)-4-thiazolyl]-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid. Analogs with basic amine substituents on the thiazole moiety were found to have antibacterial activity.     

Mild synthesis of 5-(9-ethyl-9H-carbazol-3-yl)-N-aryl-1,3,4-thiadiazol-2-amines

An efficient synthetic method for heterocycles containing both carbazole and 1,3,4-thiadiazole moieties is described. 9-Ethyl-9H-carbazol-3-carbaldehyde reacted with 4-arylthiosemicarbazides, with acetic acid as catalyst, to give 1-(9-ethyl-9H-carbazol-3-yl)methylene-4-arylthiosemicarbazides, which were further treated with manganese dioxide at room temperature in acetone to give 5-(9-ethyl-9H-carbazol-3-yl)-N-aryl-1,3,4-thiadiazol-2-amines in good to high yield. This procedure has the advantages of mild conditions, easy separation, and simple manipulation.     

New carbazole-containing monomers and polymers

Five novel vinyl monomers, all of which contain 3-substituted carbazolyl groups [i.e., N-(9-ethyl-3-carbazolyl)-maleimide, 9-ethyl-3-carbazolyl acrylamide, 9-ethyl-3-carbazolyl methacrylamide, 9-ethyl-3-hydroxymethylcarbazolyl acrylate, and 9-ethyl-3-hydroxymethylcarbazolyl methacrylate], and their corresponding polymers were synthesized. Two methods were used for the synthesis of the last two monomers.     

Syntheses and Crystal Structures of 9-Ethyl-1,3,6,8-tetra-aryl-9H-carbazole Compounds

The title compounds 9-ethyl-1,3,6,8-tetra-p-tolyl-9H-carbazole (1) and 9-ethyl-1,3,6,8-tetrakis-(4-fluoro-phenyl)-9H-carbazole (2) were synthesized and characterized by single-crystal X-ray diffraction. Thereinto, the crystal structures of compounds 1 and 2 were composed by asymmetry units. The ratio of compounds 1 and 2 to the solvent molecule cyclohexane (CYH) is 4/3. X-ray analysis reveals that the 1,3,6,8-phenyl groups are distorted at large angles relative to the planar carbazole ring. Furthermore, the luminescent and thermal properties of 1 and 2 have also been investigated. It can be seen that thermal stability of compound 1 with p-tolyl is better than that of 2 with 4-fluoro-phenyl. Fluorescence spectra analysis showed that compounds 1 and 2 have strong UV emission.     

Lactams—I The synthesis and acid hydrolysis of 4- and 5-substituted 1-benzyl-2-piperidone derivatives

In order to explain the difficulty in hydrolysing the lactam linkage of 1-benzyl-2-oxo-5-ethyl-4-piperidineacetic acid (XIV) under acid conditions, several model compounds such as 1-benzyl-2-piperidone (X), 1-benzyl-5-ethyl-2-piperidone (XI), 1-benzyl-4-ethyl-2-piperidone (XII) and 1-benzyl-2-oxo-4-piperidineacetic add (XIII) were prepared and their hydrolysis in boiling 6N HCl was studied. For each of the lactams, the hydrolysis was found to proceed to an equilibrium as shown in Table 1. Substituents at the 4- and 5-positions of the piperidone ring seemed to favour the ring form in the equilibrium between piperidones (X-XIV) and ω-amino acid hydrochlorides (type XV).     

Synthesis of a novel analog of nalidixic acid: 1-Ethyl-1,4-dihydro-4-oxo-7-(trifluororaethyl)-1,8-naphthyridine- 3-carboxylic acid

Reaction of nalidixic acid ( 1 ) with thionyl chloride and subsequent treatment with ethanol gave a mixture of ethyl 1-ethyl-1,4-dihydro-4-oxo-7-(trichloromethyl)-1,8-naphthyridine-3-carboxylate ( 3 ) and diethyl 1-ethyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3,7-dicarboxylate ( 4 ). Ethyl1-ethyl-1,4-dihydro-4-oxo-7-(trichloromethyl)-1,8-naphthyridine-3-carboxylate ( 3 ) was reacted with antimony pentafluoride to afford 1-ethyl-1,4-dihydro-4-oxo-7-(trifluoromethyl)-l,8-naphthyridine-3-carboxylic acid ( 5 ).     

1-芳基-4-吡唑-5-酰基氨基脲类化合物的合成及杀菌活性

为了寻求新的吡唑先导化合物, 用4-氯-1-甲基-3-乙基-5-吡唑甲酰肼与取代苯基异氰酸酯反应得到了14个新的1-吡唑酰基-4-芳基氨基脲类化合物. 经IR, 1H NMR, MS和元素分析对化合物的结构进行了表征. 初步生物活性实验结果表明, 在500 mg/mL浓度下, 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2-甲基苯基)氨基脲(4g), 1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2,4-二甲基苯基)氨基脲(4k)对小麦白粉病菌(Blumeria graminis)的抑制率分别达到90%和80%; 在25 mg/mL浓度下, 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-苯基氨基脲(4c)对黄瓜灰霉病菌(Botrytis cinerea)的抑制率达到70.1%; 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-苯基氨基脲(4c)和1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2-硝基苯基)氨基脲(4d)对稻瘟病菌(Pyricularia oryzae)的抑制率均达到51.3%.     

Synthesis of 2-aza analog of rosoxacin

Diazotization of 2-nitro-4-(4-pyridinyl)aniline ( 4 ) in hydrobromic acid gave the corresponding bromo derivative 5 which was treated with cuprous cyanide to give the benzonitrile derivative 6 which in turn was converted to 2-nitroacetophenone derivative 9 . Reduction of 9 followed by diazotization of the resulting amine 10 gave 7-(4-pyridinyl)cinnolin-4(1H)-one ( 11 ) which was subsequently converted to 1 -ethyl-1,4-dihydro-4-oxo-7-(4-pyridinyl)cinnoline-3-carboxylic acid ( 14 ) in three steps.     

Synthesis of substituted 2-ethyl-3-(4-hydrazinocarbonylphenyl)-4-quinazo-lones and 2-ethyl-3-(4-hydrazinocarbonylmethylphenyl)-4-quinazolones

Some substituted 2-ethyl-3-(4-hydrazinocarbonylphenyl)-4-quinazolones and 2-ethyl-3-(4-hydrazinocarbonylmethylphenyl)-4-quinazolones were synthesized and characterized by their sharp melting points, elemental analyses and spectral data.     

Synthesis of 6-substituted 1-alkoxy-5-alkyluracils

Synthesis of 6-substituted 1-alkoxy-5-alkyluracils 2a-c have been achieved from readily accessible 2-alkyl-3,3-di(methylthio)acryloyl chlorides 4a,b in high overall yields. Treatment of 4a,b with silver cyanate followed by reaction of the resulting isocyanates 5a,b with an appropriate alkoxyamine afforded N-alkoxy-N′-[2-alkyl-3,3-di(methylthio)acryloyl]ureas 6a,b in 85–88% yields. Cyclization of 6a,b in acetic acid containing methanesulfonic acid followed by oxidation with 3-chloroperoxybenzoic acid gave high yields of 1-alkoxy-5-alkyl-6-(methylsulfonyl)uracils 9a,b. Nucleophillic addition-elimination reaction of 9a,b with sodium azide, phenylthiol, or phenylselenol produced 6-azido-1-butoxythymine ( 2a , 98%), 5-ethyl-1-(2-phenoxyethoxy)-6-(phenylthio)uracil ( 2b , 95%), or 5-ethyl-1-(2-phenoxyethoxy)-6-(phenylselenenyl)uracil ( 2c , 91%).     

Synthesis of Branched Hydrazones by Reaction of N-(2,3-Epoxypropyl) Derivatives of Hydrazones with Benzenediols

A series of branched hydrazones have been prepared by reaction of N-(2,3-epoxypropyl) derivatives of 9-ethyl-3-carbazolecarbaldehyde and 4-diethylamino-benzcarbaldehyde phenylhydrazones with 1,2-, 1,3-, and 1,4-benzenediols. It was found that the reaction rate depends on the polarity of solvents.     

Condensation of 1-Substituted 1,2,3,9a-Tetrahydro-9H-imidazo[1,2-a]indol-2-one Derivatives with Aromatic Aldehydes

Condensation of 1-alkyl-, 1-allyl-, and 1-benzyl-1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-ones with benzaldehydes in acetic acid and subsequent treatment of the reaction mixture with potassium hydroxide afforded 1-substituted 9a-(2-phenylethenyl)-1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-one derivatives. 1-Methyl- and 1-ethyl-9a-[2-(4-dimethylaminophenyl)ethenyl]-1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-ones were synthesized by alkylation of 9a-[2-(4-dimethylaminophenyl)ethenyl]-1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-one with methyl- and ethyl iodides in DMF in the presence of a strong base.     

Cationoid rearrangements in reactions of perfluoro-1-arylbenzocyclobutenes with antimony pentafluoride

In the presence of antimony pentafluoride at 130 °C, the four-membered ring of perfluoro-1-(2-ethylphenyl)benzocyclobutene (2) undergoes cleavage, forming perfluoro-2-ethyl-2′-methyldiphenylmethane (5). Compound 5 is converted, under the action of SbF₅ at 170 °C, to perfluoro-8,9-dimethyl-1,2,3,4-tetrahydrofluorene (8). Perfluoro-1-(4-ethylphenyl)benzocyclobutene (3) remains unchanged at 130 °C, whereas at 170 °C it gives a mixture of perfluorinated 4′-ethyl-2-methyldiphenylmethane (9), 6-ethyl-1,2,3,4-tetrahydroanthracene (11) and 2-ethyl-9,10-dihydroanthracene (12). When heated with SbF₅ at 170 °C, perfluoro-1-phenylbenzocyclobutene (1) remains unchanged. Solution of compounds 2, 3, 5 and 9 in SbF₅-SO₂ClF generated the perfluorinated 1-(2-ethylphenyl)-1-benzocyclobutenyl (29), 1-(4-ethylphenyl)-1-benzocyclobutenyl (30), 2-ethyl-2′-methyldiphenylmethyl (31) and 4′-ethyl-2-methyldiphenylmethyl (32) cations, respectively.     

Synthesis and photoluminescence properties of 8-hydroxyquinoline derivatives and their metallic complexes

Three new 8-hydroxyquinoline derivatives, i.e. 5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), ¹H nuclear magnetic resonance (¹H NMR), Fourier transform infrared spectrometer (FTIR), mass spectrometry (MS) spectra and elemental analyses. Their fluorescence properties were studied by photoluminescence, which indicated that the luminescence wavelength of 5-and 2-substitued-8-hydroxyquinoline derivatives shifted to red in comparison with that of 8-hydroxyquinoline. Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol and its zinc complex showed long lifetime in benzene solution. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(3): 402–408 [译自: 有机化学]     

Isolation and molecular structures of novel organotellurium(iv) halides, oxyhalide and mixed halide

The formation of chiral (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(iv) trihalides (trichloride (5), tribromide (6) and triiodide (7)) and (R)-[2-(4-ethyl-2-oxazolinyl)phenyl]tellurium(ii) bromide (8) is described. The molecular structure of the first chiral organotellurium(iv) triiodide (7) is discussed. The most interesting feature of the structure of 5 is the observation of the shortest intramolecular TeN distance for any organotellurium(iv) trichloride. Compounds 5 and 6 do not undergo electrophilic addition reaction with olefins. Attempted addition reaction of 6 with olefin in methanol leads to the isolation of the rare partially hydrolysed tellurium(iv) halide, methyl-2-(dibromooxotellurium)benzoate (9). Novel stable mixed halide 12 was isolated from the bromination of 11. DFT calculations indicate that both the isomers 12a and 12b have similar stability.     

Potential cerebral perfusion agents. Synthesis and evaluation of new radioiodinated barbituric acid analogs

Two new ¹²⁵I-labeled barbituric acid analogs, 5-ethyl-5-(E-1-iodo-1-penten-5-yl)2-thiobarbituric acid ( 4 ) and 5-ethyl-5-( m -iodophenyl)barbituric acid ( 7 ), have been prepared and evaluated in rats as potential cerebral perfusion agents. Annulation of 2-ethyl-2-(E-1-iodo-1-penten-5-yl)malonate ( 3 ) with thiourea in the presence of sodium ethoxide gave the 5-ethyl-5-(E-1-iodo-1-penten-5-y1)-thiobarbituric acid ( 4 ). Diethyl 2-ethyl-2-phenyl-malonate was treated with thallium(III) trifluoroacetate followed by addition of aqueous potassium iodide to provide diethyl 2-ethyl-2-(m-iodophenyl)malonate ( 10 ). The malonic ester derivative 10 was condensed with urea in the presence of sodium hydride to give the desired 5-ethyl-5-(m-iodophenyl)barbituric acid ( 7 ), and a decarbethoxylation product, 2-(m-iodophenyl)butyric acid ( 11 ). Iodine-125-labeled 4 and 7 were synthesized in the same manner and the tissue distribution of these new agents evaluated in rats. Both [¹²⁵I] 4 and [¹²⁵I] 7 showed high brain uptake. Significant in vivo deiodination was detected with [¹²⁵I] 4 whereas [¹²⁵I] 7 was found to be stable to deiodination.     

Preparation of highly potent and selective non-peptide antagonists of the arginine vasopressin V1A receptor by introduction of a 2-ethyl-1H-1-imidazolyl group

To find a new series of arginine vasopressin (AVP) V1A receptor antagonists, the influence of the 2-phenyl group of 2-phenyl-4'-[(2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]benzanilide (7) was investigated. Replacement of the 2-phenyl group by a 2-ethyl-1H-imidazol-1-yl group was effective in yielding a V1A-selective compound. Moreover, this imidazolyl group was introduced in the same position in YM-35471 (6), and further studies of these compounds were performed. Consequently, we found that the (Z)-4'-({4,4-difluoro-5-[(N-cyclopropylcarbamoyl)methylene]-2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl}carbonyl)-2-(2-ethyl-1H-1-imidazol-1-yl)benzanilide (9f) exhibited highly potent affinity and selectivity, and was the most potent antagonist for the V1A receptor among our compounds. The synthesis and pharmacological evaluation of these compounds are described in this paper.     

Synthesis of 9-azolyl-3-(4-phenyl-4h-1,2,4-triazol-3-yl)-4h,8h-pyrano-[2,3-<Emphasis Type="Italic">f</Emphasis>]chromene-4,8-diones

The reaction of 6-ethyl-8-formyl-7-hydroxy-3-(4-phenyl-4H-1,2,4-triazol-3-yl)chromone with 2-azolyl-acetonitriles gave 8-iminopyrano[2,3-f]chromen-4-ones, whose acid hydrolysis led to pyrano-[2,3-f]chromene-4,8-diones containing azaheterocyclic substituents at C-3 and C-9.