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Kamal M. El-Shaieb 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3):675-681
A mixture of equimolar quantities of dimethyl acetylenedicarboxylate ( 2 ) with either 2-mercaptoperimidine ( 1 ) or 2-mercaptobenzimidazole ( 5 ) was heated in absolute benzene in the presence of triphenylphosphine as a catalyst under reflux conditions for 1 h (the reaction was monitored by TLC until the consumption of the starting materials). The solvent was concentrated under vacuum and the residue was subjected to chromatographic plates using toluene-ethylacetate (2:1) as an eluent. The products in each reaction were separated as two migrating zones. Each zone was removed from the plate and recrystallized from the appropriate solvent. The products of the first reaction are 10-methoxy-11-oxo-11H-8-thia-7,11a-diaza-benzo[de]anthracene-9-carboxylic acid methyl ester ( 3 ) and 8-thia-7,10a-diaza-cyclopenta[a]phenalene-9,10-dicarboxylic acid dimethyl ester ( 4 ), while the products of the second reaction are 3-methoxy-4-oxo-4H-1-thia-4a,9-diaza-fluorene-2-carboxylic acid methyl ester ( 10 ) and benzo[4, 5]imidazo[2,1-b]thiazole-2,3-dicarboxylic acid dimethyl ester ( 11 ). The mechanisms of the observed reactions are suggested. 相似文献
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Triphenylphosphine catalyzes the reaction between 2-hydroxy-1-naphthaldehyde and π-deficient acetylenes to give the newly prepared benzo[f]chromenes. The mechanism for the formation of products is discussed. 相似文献
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Aly Ashraf A. Hassan Alaa A. Mohamed Nasr K. El-Shaieb Kamal M. Makhlouf Maysa M. Bräse Stefan Nieger Martin 《Research on Chemical Intermediates》2019,45(2):613-631
Research on Chemical Intermediates - The reaction of N-substituted hydrazinecarbothioamides with both 2-(bis(methylthio)methylene)malononitrile and ethyl 2-cyano-3,3-bis(methylthio)acrylate... 相似文献
4.
Hassan Alaa A. Aly Ashraf A. Mohamed Nasr K. El-Shaieb Kamal M. Makhlouf Maysa M. Bräse Stefan Nieger Martin Brown Alan B. 《Research on Chemical Intermediates》2020,46(2):1571-1585
Research on Chemical Intermediates - The reaction between N-substituted alkenylidene hydrazinecarbothioamides and two molar amounts of tetracyanoethylene (TCNE) in anhydrous THF at room temperature... 相似文献
5.
Reactions of 1,8-diaminonaphthalene with some selected π-acceptors are reported herein. The reaction of the 1,8-diaminonaphthalene with 1,1,2,2-tetracyanoethylene (TCNE) and 7,7′,8,8′-tetracyanoquinodimethane (TCNQ), via different modes of cyanovinylation, yielded (2E)-2,3-bis-(8-aminonaphthalen-1-ylamino)-but-2-enedinitrile and 2-[4-(1H,3H-perimidin-2-ylidene)cyclohexa-2,5-dienylidene]malononitrile, respectively. On the other site, the reaction of the target molecule with 2-dicyanomethyleneindane-1,3-dione (CNIND), 2-(2,4,7-trinitro-9H-fluoren-9-ylidene)propane-dicarbonitrile (DTF) and 2,3-dichloro-4,5-dicyano(2,3,4,5-tetrachloro)-1,4-benzoquinones (DDQ and CHL-p) afforded perimidin and pleiadene derivatives. 相似文献
6.
Reactions of N,N;-disubstituted hydrazinecarbothioamides 8a-c and substituted thioureidoethylthioureas 9a-c with 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil, 10a) and 2,3,5,6-tetrabromo-1,4-benzoquinone (bromanil, 10b) to form N,N;-disubstituted [1,3,4]thiadiazole-2,5-diamines 11a-c, 6,7-dichloro-3-substituted amino-1H-benzo[1,3,4]- thiadiazine-5,8-diones 12a-c, 2,3,7,8-tetrahalothianthrene-1,4,6,9-tetraones 13a,b, 5,6,8- trihalo-7-oxo-3,7-dihydro-2H-quinoxaline-1-carbothioic acid substituted amides 14a-c, 15a-c and 7-substituted imino-[1,3,6]thiadiazepane-3-thiones 16a-c are reported. Rationales for the observed conversions are presented. 相似文献
7.
Alaa A. Hassan Kamal M.A. El-Shaieb Nasr K. Mohamed Hendawy N. Tawfeek Stefan Bräse Martin Nieger 《Tetrahedron letters》2014
Mesoionic 1,2,4-triazolium-3-thiolate derivatives were synthesized from the reaction of N-substituted-2-phenylhydrazinocarbothioamides with tetracyanoethylene (TCNE) to give tricyanovinyl intermediates, followed by heterocyclization to afford 5-(1-amino-2,2-dicyano-vinyl)-4-substituted-1-phenyl-4H-1,2,4-triazol-1-ium-3-thiolates in 67–76% yields. The structures of the products have been confirmed unambiguously by single crystal X-ray structure analyses. A rationale for the formation of the products is presented. 相似文献
8.
Phenylbiguanide reacts with some π-acceptors such as TCNE, TCNQ, CNIND, DCNQ, and CHL-o, if any. opy; 2003 Wiley Periodicals, Inc. Heteroatom Chem 15:63–66, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10213 相似文献
9.
A. M. El-Shaieb 《The Journal of the Operational Research Society》1978,29(5):469-476
Alfred Weber reduced the problem of locating a firm under the conditions that all cost elements other than those which vary regularly with space are held constant, to that of determining the point(s) of minimum transportation costs. This paper presents a survey of the techniques used to solve this problem and gives an efficient Quadratic Approximation Search Technique which was coded in FORTRAN IV and tested on a number of problems for it. 相似文献
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