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1.
Zorica M. Bugar?i? Biljana Mojsilovi? Ljiljana Marjanovi? Stanimir Konstantinovi? 《Monatshefte für Chemie / Chemical Monthly》2000,17(6):1091-1096
The reaction of some alkenols with tetrachloromethane in the presence of a radical initiator was investigated. Regarding the effects of structural features of the starting alkenol (number and position of methyl substituents at the double bond and at the carbinol carbon atom, constitutional relationship between the double bond and the hydroxyl group) there are two possible competing reactions: addition and cyclization. In the case of the simplest alkenols (without substituents and with a more remote double bond) addition occurs; mono- and disubstituted secondary and tertiary Δ4- and Δ5-alkenols cyclize in high yields to give the corresponding cyclic ethers. 相似文献
2.
Summary. N′-Arylacetonitrilimines were generated from acetohydrazonyl chlorides and reacted with mercaptoalkanoic acids forming 4-aryl-5-oxo-3-thiahexanoic
acids. These were cyclized by reaction with dicyclohexyl carbodiimide yielding 2-acetyl-4-aryl-6H-1,3,4-thiadiazin-5-ones.
Received November 13, 2001. Accepted January 9, 2002 相似文献
3.
Osama I. Abd El-Salam 《Monatshefte für Chemie / Chemical Monthly》2000,131(9):959-965
Summary. The synthesis of new pyrimido[5,4-a]indolizines by reaction of 2-aminoindolizine-1-carbonitrile or ethyl 2-aminoindolizine-1-carboxylate with various electrophilic
reagents is described. The structure of the products was confirmed by their elemental analysis and IR, 1H NMR, and mass spectra. The results of a preliminary antimicrobial screening are also presented.
Received February 4, 2000. Accepted (revised) March 8, 2000 相似文献
4.
Suyou Liu Xuhong Qian Jing Chen Gonghua Song 《Monatshefte für Chemie / Chemical Monthly》2000,131(9):953-957
Summary. Thiatetraazaindenone derivatives were synthesized by reaction of 3-substituted 1,2,4-triazole-5-thiols with N-substituted
N-chloromethyl carbamoyl chlorides. A series of thiatriazafluorenone derivatives were also prepared by reaction of benzimidazole
derivatives with the same substrate. Some of the new compounds show fungicidal, herbicidal, and insecticidal activity.
Received February 14, 2000. Accepted (revised) April 11, 2000 相似文献
5.
Jan Zawadiak Mirosław Danch Mariola Pigulla 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):821-824
Summary. Syntheses of novel primary-tertiary bisperoxides were carried out under phase transfer catalysis conditions. The bisperoxides
were obtained in good yields, the reaction times not exceeding four hours.
Received January 15, 2001. Accepted (revised) February 9, 2001 相似文献
6.
Jozef Saloň Viktor Milata Nadežda Prónayová Ján Leško 《Monatshefte für Chemie / Chemical Monthly》2000,131(3):293-299
Summary. Reaction of 5-aminoquinoxaline with alkoxymethylene derivatives affords the corresponding quinoxalinoaminoethylenes. These
undergo a thermal cyclization to yield angularly annelated 10H-pyrido[2,3-f]quinoxalines. The structures of all products were deduced from their IR, UV, mass, 1H, and 13C NMR spectra.
Received September 24, 1999. Accepted November 18, 1999 相似文献
7.
Summary. Upon irradiation of 3,4-di-O-benzyl-hypericin and proton sponge (bis-1,8-N,N-dimethylamino-naphthalene) in benzene solution, a stable radical ion pair formed which exhibited an intense absorption
band around 800 nm. This was advanced by UV/Vis, NMR, and ESR spectroscopy. In presence of oxygen, irradiation of this photoproduct
led to an activated oxygen species which then attacked the proton sponge.
Received July 17, 2000. Accepted July 20, 2000 相似文献
8.
Rafat M. Mohareb Fatma A. Al-Omran Jonathan Z. Ho 《Monatshefte für Chemie / Chemical Monthly》2002,133(11):1443-1452
Summary. 2-Amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene with ethyl β-amino-α-cyano-γ-ethoxycarbonylcrotenoate yields the corresponding amide derivative. That compound
reacts with benzenediazonium chloride to give the phenyl hydrazone derivative. This type of compounds was cyclized to give
pyridazine and pyridine derivatives, respectively. Chemical reactivities of the latter were studied to give fused heterocyclic
compounds with antimicrobial activities.
Corresponding author. E-mail: rmmohareb@hotmail.com
Received February 8, 2002; accepted (revised) March 28, 2002 相似文献
9.
The iodine-azide reaction induced by eight thiosemicarbazones was investigated. Inducing properties of thiosemicarbazones
are different and depend on the parent carbonyl compound used for synthesis. The inductor coefficients of the examined thiosemicarbazones
vary from 61 to 176. Optimum conditions for the determination of microamounts of thiosemicarbazones are given. The detection
limit for the determination by the back-titration method depends on the inducing activity and is 0.9 μg for phenyl-thiosemicarbazones
and 2 μg for diethyl-thiosemicarbazone in a 5-mL sample, and this corresponds to a concentration of 0.9 × 10−6 mol/L and , respectively. The automatic titration with the diluted iodine solution decreases the detection limit to about 50 ng in a
10-mL sample.
Received October 28, 1998. Revision April 9, 1999. 相似文献
10.
Jarosłlaw Lewkowski Jacques Mortier Michel Vaultier 《Monatshefte für Chemie / Chemical Monthly》2000,131(7):707-710
Summary. Reaction of boron tribromide with triethyl phosphite led to the formation of triethyl tribromoborophosphate 1, a complex bearing a P→B bond.
Received November 19, 1999. Accepted (revised) January 21, 2000 相似文献
11.
Czeslawa Orlewska Rafat M. Shaker Martin Dees Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2000,131(8):889-893
Summary. The reaction between push-pull olefins of the acyloxymethylidene-malononitrile type and α, β-unsaturated hydrazones affords
selectively 5-alkyl-2-cyano-6-(N′,N′-dimethylhydrazono)-hexa-2,4-dienenitriles. No [4+2]-cycloaddition products were detected.
The structure elucidation of the obtained compounds and possible reaction mechanisms are discussed.
Received March 9, 2000. Accepted March 20, 2000 相似文献
12.
Gülcemal Yıldız Haluk Akkuş Ahmet Gül 《Monatshefte für Chemie / Chemical Monthly》2001,132(6):659-667
Summary. Some porphyrazines with dimethylamino- or trimethylammoniumethylsulfanyl substituents were studied in dichloromethane or
dimethylsulfoxide solution by cyclic voltammetric methods. The cyclic voltammogram of metal free octakis-(dimethyl-aminoethylsulfanyl)-porphyrazine is characterized by three one-electron reduction waves which show quasi-reversible behaviour at all sweep rates observed; the same holds for its cobalt(II) derivative. The quaternized octacationic
derivative, however, exhibits four one-electron reduction waves which are reversible at all sweep rates. The reaction mechanisms
and diffusion coefficients were investigated.
Received October 17, 2000. Accepted (revised) December 11, 2000 相似文献
13.
Summary. Treatment of 5-amino-6-cyclohex-2-enyl-1, 3-dimethyl-uracil with pyridinium hydrotribromide or hexamethylenetetrammonium
hydrotribromide furnished the corresponding linear heterocyclic 6-bromo-1, 3-dimethylhexahydroindolo[3,2-d]pyrimidine-2, 4-diones in 90% yield. Reaction of the same educt with molecular bromine in chloroform afforded the bicyclic
9-bromo-1, 3-dimethylhexahydrobicyclo[3.3.1]indolo[3,2-d]pyrimidine-2, 4-diones in 85% yield. Upon treatment of the above substrate with cold concentrated sulfuric acid, a mixture
of 1, 3-dimethylhexahydro-indolo[3, 2-d]pyrimidine-2, 4-dione (28%) and 1, 3-dimethylhexahydrobicyclo[3.3.1]indolo[3, 2-d]pyrimidine-2, 4-dione (60%) was obtained.
Received August 4, 2000. Accepted (revised) November 15, 2000 相似文献
14.
R. F. W. Bader 《Theoretical chemistry accounts》2002,107(6):381-382
It is shown that the statement made by Cassam-Chenai and Jayatilaka regarding the atoms of AIM to the effect that “In particular,
we shall demonstrate that these atoms are not a consequence of the Schwinger variation principle, as has been claimed” is
false.
Received: 15 June 2001 / Accepted: 10 October 2001 / Published online: 19 June 2002 相似文献
15.
Ali Sharifi Hossein Farhangian Farshid Mohsenzadeh M. R. Naimi-Jamal 《Monatshefte für Chemie / Chemical Monthly》2002,133(2):199-204
Summary. Terminal alkynes, secondary amines, and formaldehyde undergo a Mannich reaction at room temperature in the presence of CuCl on Al2O3 without any organic solvent as reaction medium. The reaction can be promoted by microwave irradiation and is complete within
one minute.
Received May 2, 2001. Accepted (revised) June 25, 2001 相似文献
16.
Summary. A new simple, rapid, sensitive, and selective method is proposed for the microdetermination of mercury. Mercury(II) forms
insoluble complexes with 2,3-dichloro-6-(2-hydroxy-3,5-dinitrophenylazo)-quinoxaline (1), 2,3-dichloro-6-(5-amino-3-carboxy-2-hydroxy-phenylazo)-quinoxaline (2), 2,3-dichloro-6-(2,7-dihydroxynaphth-1-ylazo)-quinoxaline (3), and 2,3-dichloro-6-(3-carboxy-2-hydroxy-naphth-1-ylazo)-quinoxaline (4) in aqueous acidic medium; the complexes can be made soluble by the action of an anionic surfactant. The solution of the
pink coloured compounds is stable for at least 24 h. Beer’s law is obeyed over the concentration range from 0.1 to 2.8 μg · cm−3 of mercury. For a more accurate analysis, Ringbom optimum concentration ranges were found to be 0.25–2.5 μg · cm−3. The molar absorpitivity, Sandell sensitivity, and relative standard deviations were also calculated. A slight interference from Pd2+ and Cd2+ is exhibited by the first three ligands, whereas the last one is only negligibly affected by these metal ions. Strong interference
from Ag(I) is evident for all ligands, whereas alkali, alkaline earth, and other transition metals tested posed negligible
interference. 15 μg · cm−3 of Cd2+ and Pd2+ or 10 μg · cm−3 of Ag+ can be tolerated if 1.0 mg of potassium bromide and 2.0 mg of citrate as masking agents are added for the determination of
1.5 μg · cm−3 of mercury(II). The method was applied to the determination of methyl- and ethylmercury chloride and the analysis of environmental
water samples.
Received August 7, 2000. Accepted (revised) October 18, 2000 相似文献
17.
Sham M. Sondhi Nidhi Singhal Rajeshwar P. Verma Sudershan K. Arora Rakesh Shukla Ram Raghubir 《Monatshefte für Chemie / Chemical Monthly》2000,131(5):501-509
Summary. Upon condensation with 4-isothiocyanato-4-methyl-2-pentanone, 2,3-diaminonaphthalene and N-aminoethyladenosine gave in good
yields substituted pyrimidonaphthoimidazole and imidazopyrimidine thione. Refluxing pyrimidobenzthiazole with methanol H2SO4 at pH∼1 resulted in S-methyl pyrimidobenzthiazole in moderate yield. Pyrimidobenzimidazole derivatives could be reacted to S-alkylated
and N-acylated derivatives by refluxing with ethyl bromoacetate in the presence of anhydrous potassium carbonate in THF and by heating in an acetic acid/acetic anhydride mixture. Heating of pyrimidobenzimidazole with 75% aqueous H2SO4 on a water bath ended up in a rearranged product. All compounds gave correct 1H NMR, IR, and HR mass spectra. Results of antiinflammatory, analgesic, and anticancer activity screening of the new compounds
are described.
Received October 29, 1999. Accepted (revised) January 13, 2000 相似文献
18.
Herman Gershon Donald D. Clarke John J. McMahon Muriel Gershon 《Monatshefte für Chemie / Chemical Monthly》2001,132(7):833-838
Summary. 2,5-, 3,5-, 3,6-, 3,7-, 4,5-, 5,6-, 5,7-, and 6,7-dibromo-8-quinolinols were prepared and tested against six fungi (Aspergillus niger, Aspergillus oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, and Trichophyton mentagrophytes) in Sabouraud dextrose broth. Most of the compounds were strongly antifungal, inhibiting five of the fungi below 1μg/cm3, but were somewhat less fungitoxic than the corresponding chloro analogues. M. cirinelloides was not inhibited by any of the compounds except 4,5-dibromo-8-quinolinol. This high level of fungitoxicity is attributed
to intramolecular synergism.
Received December 28, 2000. Accepted (revised) February 3, 2001 相似文献
19.
Synthesis of Novel 2-Aminothiophene-3-carboxylates by Variations of the Gewald Reaction 总被引:1,自引:0,他引:1
Hans-Peter Buchstaller Carsten D. Siebert Ralf H. Lyssy Ina Frank Adil Duran Rudolf Gottschlich Christian R. Noe 《Monatshefte für Chemie / Chemical Monthly》2001,132(2):279-293
Summary. The synthesis of the title compounds through variations of the Gewald reaction is presented. Knoevenagel condensation of methylketone derivatives with methyl cyanoacetate and subsequent treatment of the α,β-unsaturated nitriles
with sulfur and amine resulted in the corresponding 2-aminothiophenes 5 or isomers 9 and 10. Reaction of methylketone derivatives bearing a leaving group at the methyl group under modified Gewald conditions selectively led to the formation of 4-substituted 2-aminothiophenes 9a and 12. The introduction of the sulfur atom occurs through nucleophilic displacement with sodium sulfide.
Received July 5, 2000. Accepted (revised) August 23, 2000 相似文献
20.
Elka Vassileva Janos Sapi Jean-Yves Laronze Catherine Mirand Jean Lévy 《Monatshefte für Chemie / Chemical Monthly》2002,133(2):151-156
Summary. 2′-Dimethylamino-1′-trifluoroacetyl-2-vinylindole derivatives were prepared by trifluoroacetic anhydride assisted oxidation.
Received July 20, 2001. Accepted (revised) September 24, 2001 相似文献