Enaminones in Heterocyclic Synthesis: A Novel Route to Polyfunctionalized Substituted Thiophene, 2,3-Dihydro-1,3,4-Thiadiazole and Naphtho[1,2- b ] Furan Derivatives
作者:Zaghloul E. Kandeel、Khadija M. Al-Zaydi、Ebtisam A. Hafez、Mohamed H. Elnagdi
DOI:10.1080/10426500210232
日期:2002.1.1
The enaminones 1a , b reacted with phenylisothiocyanate to afford the thioanilides 2a , b . The latter could be utilized to synthesize several new polysubstituted thiophenes 9a-f , and 1,3,4-thiadiazoles 12a-f .
Studies on enaminonitriles: A new synthesis of 1,3-substituted pyrazole-4-carbonitrile
作者:Said Ahmed Soliman Ghozlan、Ismail Abdelshafy Abdelhamid、Mohamed Hilmy Elnagdi、Hatem Moustafa Gaber
DOI:10.1002/jhet.5570420623
日期:2005.9
1-p-chlorophenylpyrazole-4-carbonitrile (5a) condensed with hydrazine hydrate to yield the bishydrazone 10 and with dimethylformamide dimethylacetal to yield 1-aryl-3-(3-dimethylamino)acryloyl pyrazole-4-carbonitrile (11). This enamine reacts with hydrazine hydrate to yield the pyrazolylpyrazole (12) and with naphthoquinone to yield the 3-naphthofuranoyl pyrazole 13. The pyra-zolyl pyridine derivative 14
3-二乙基氨基丙烯腈(1)与酰肼卤化物(2a-d)反应,得到1,3-二取代的吡唑-4-腈5a-d。乙酰1- p -chlorophenylpyrazole -4-甲腈(5a中与水合肼缩合),得到双腙10和二甲基甲酰胺二甲基缩醛,得到1-芳基-3-(3-二甲基氨基)丙烯酰基吡唑-4-甲腈(11)。该烯胺与水合肼反应,生成吡唑基吡唑(12),与萘醌反应,生成3-萘呋喃酰基吡唑13。对吡唑-唑基吡啶衍生物14进行如下处理。在乙酸铵存在下用乙酰丙酮11。化合物11被加上p -chlorobenzene氯化重氮,得到腙16,将其用还耦合p -chlorobenzenediazonium酰氯,得到的甲簪18。
Simple and convenient routes to new polyheterocycles incorporating pyrazole, thiazole, thiophene, and 1,3,4-thiadiazole moieties
作者:Zaghloul E. Kandeel、Kamal M. Dawood、Eman A. Ragab、Ahmad M. Farag
Synthesis of some new benzofuran-based thiophene, 1,3-oxathiole and 1,3,4-oxa(thia)diazole derivatives
作者:Kamal M. Dawood、Ahmad M. Farag、Hatem A. Abdel-Aziz
DOI:10.1002/hc.20298
日期:2007.4
afforded the thioacetanilide derivative 3, which when reacted with α-haloketones, α-halodiketones, and hydrazonoyl chlorides gives thiophene, 1,3-oxathiole, and 1,3,4-thiadiazole derivatives 6a,b, 10a,b and 14a–g, respectively. Treatment of 3-methyl-2-benzofurancarboxylic acid hydrazide (15) with benzaldehyde followed by bromine afforded the 1,3,4-oxadiazole derivative 18. Treatment of the acid hydrazide
Relative stabilities of Z- and E-isomers, calculated with the RHF/6-31G∗ ab initio method, range between 0.7 and 2.1 kcal/mol. The Z-isomer is detected to be thermodynamically more stable for studied compounds. X-ray structure determination of 2-dimethylamino-N-phenyl-2-phenylhydrazonoacetamide revealed E- and Z-isomers (ratio 1:1) in the crystal. The different intra- and intermolecular hydrogen bond