共查询到20条相似文献,搜索用时 219 毫秒
1.
Jií Hanusek Pavel Drabina Milo Sedlk Pavel Rosa 《Journal of heterocyclic chemistry》2006,43(5):1281-1285
Acylation of 2‐amino‐N‐methyl‐thiobenzamide with substituted benzoyl chlorides has been used to synthesize the corresponding 2‐benzoylamino‐N‐methylthiobenzamides. Subsequent sodium methoxide‐catalyzed ring closure gives the corresponding 3‐methyl‐2‐phenylquinazoline‐4‐thiones. These compounds were characterized by means of their 1H‐ and 12C‐NMR spectra. The kinetics of the cyclization reaction has been followed with UV‐VIS spectroscopy at 100 °C in methanolic solutions of sodium methoxide. 相似文献
2.
Hiroshi Maruoka Kenji Yamagata Fumi Okabe Yukihiko Tomioka 《Journal of heterocyclic chemistry》2006,43(4):859-865
The unusual formation of 1‐acyl‐1,2‐dihydro‐3H‐pyrazol‐3‐ones starting from 3‐acyloxypyrazoles by Fries‐type rearrangement is described. Under normal conditions, acylation of 2,4‐dihydro‐3H‐pyrazol‐3‐ones 1 and 2 with acid chlorides or anhydrides in the presence of triethylamine gave the corresponding 3‐acyloxypyrazoles 3a‐f and 4a‐f . Treatment of 3a‐c and 4a‐f with Lewis acid, e.g. titanium(IV) chloride and tin(IV) chloride, caused migration of acyl groups to afford the corresponding 1‐acyl‐1,2‐dihydro‐3H‐pyrazol‐3‐ones 5a‐c and 6a‐f . Interestingly, the reactions of 3‐acyloxypyrazoles 3e and 3f with tin(IV) chloride provided the corresponding tin(IV) complexes 8e and 8f . 相似文献
3.
The cyclocondensation reaction of compound 1 in boiling hydrochloric acid had an unexpected course. Instead of supposed 5,11‐dihydro‐quinoxalino[2,3‐b]quinoline 6a , 2‐(indol‐2‐yl)‐benzimidazole 4 was isolated as the major product. 相似文献
4.
Yansong J. Lu Bin Hu Mahavir Prashad Shaum Kabadi Oljan Repi
Thomas J. Blacklock 《Journal of heterocyclic chemistry》2006,43(4):1125-1127
Lithiation of N‐protected‐2,3‐dihydro‐1,4‐benzoxazines is described. Lithiation of N‐(tert‐butoxycarbonyl)‐2,3‐dihydro‐1,4‐benzoxazine ( 1 ) with BuLi/TMEDA occurred in the α‐position to nitrogen on the heterocyclic ring, leading to the unexpected ring‐opened product 3 . On the other hand, lithiation of N‐methyl‐2,3‐dihydro‐1,4‐benzoxazine ( 4 ) took place at the oxygen‐adjacent ortho‐position of the aromatic ring. 相似文献
5.
Alicyclic N‐substituted 1,3‐amino alcohols 13‐18 were prepared in a facile way in a one‐pot procedure from 1,3‐oxazines 5‐8 in the presence of a ketone 9‐12 . The complex reaction involves palladium‐catalyzed reduction, debenzylation and/or transimination and further reduction. 相似文献
6.
Sergey M. Desenko Evgeny S. Gladkov Svetlana V. Shishkina Oleg V. Shishkin Sergey A. Komykhov Valery D. Orlov Herbert Meier 《Journal of heterocyclic chemistry》2006,43(6):1563-1567
The condensation of 5‐amino‐4‐phenyl‐1,2,3‐triazole ( 1 ) with chalcones 2a‐e or 3‐dimethylamino‐propiophenone ( 4f ) leads to the 6,7‐dihydro‐(1,2,3)‐triazolo[1,5‐a]pyrimidines 3a‐f. The equilibrium of 3 and the tautomeric 4,7‐dihydro‐(1,2,3)‐triazolo[1,5‐a]pyrimidines 3′ is described. 相似文献
7.
Zhan‐Hui Zhang Jian‐Jiong Li Yuan‐Zhe Gao Yu‐Heng Liu 《Journal of heterocyclic chemistry》2007,44(6):1509-1512
Iodine was found to be an efficient catalyst for the synthesis of 2‐substituted benzimidazoles by the condensation of orthoesters and 1,2‐phenylenediamines in good to excellent yields under mild reaction conditions. 相似文献
8.
9.
Karel D. Klika Kalevi Pihlaja Jn Imrich Mria Vilkov Juraj Bernt 《Journal of heterocyclic chemistry》2006,43(3):739-743
N‐Acridin‐9‐yl methyl N′‐acridin‐9‐yl thiourea spontaneously spiro cyclises via nucleophilic attack of the methylene carbon onto the C‐9 of the other acridine moiety. The thiourea, upon reaction with bromoacetonitrile, provided a spiro fused‐bicyclic product displaying unusual dynamic behavior. 相似文献
10.
A series of novel title compounds have been designed and synthesized by a multi‐step reaction, the stereochemistry of the reaction was investigated, the structures of all compounds prepared have been confirmed by 1H NMR, IR, EI‐MS spectroscopy and elemental analysis. The crystal structures of cis 6b and trans 6b were determined by single crystal X‐ray diffraction. The results of preliminary bioassay indicate that some compounds possess a certain extent inhibition effect against aphides at the concentration of 250 ppm. 相似文献
11.
Lucina Arias Hactor Salgado‐Zamora Elena Campos Alicia Reyes Humberto Cervantes Edward C. Taylor 《Journal of heterocyclic chemistry》2006,43(3):565-569
In some nucleophilic substitution reactions of 2‐cyano‐3‐nitroimidazo[1,2‐a]pyridine, nitrogen (alkylamines, guanidine) and oxygen nucleophiles (alkoxides) underwent substitution of the 2‐cyano group, while sulfur nucleophiles (alkylthiols) underwent substitution of the 3‐nitro group. 相似文献
12.
Gerardo Blanco Jos M. Quintela Carlos Peinador 《Journal of heterocyclic chemistry》2006,43(4):1051-1056
An efficient one‐pot access for the synthesis of the previously unreported tetracyclic fused pyrimido‐[4″,5″:4′,5′]thieno[3′,2′:4,5]thieno[3,2‐d]pyrimidine ( 3 ) and 1,2,3‐triazine[4″,5″:4′,5′]thieno‐[3′,2′:4,5]thieno‐[3,2‐d]‐1,2,3‐triazine ( 5 ) heteroaromatic nitrogen ligands is described. The title compounds 3 and 5 were obtained from 3,4‐diaminothieno[2,3‐b]thiophene‐2,5‐dicarbonitrile and phosgeniminium chloride and sodium nitrite/HCl, respectively. Substituted condensed thieno[2,3‐b]thiophene derivatives 4 and 6 were synthesized by nucleophilic displacement of the chloroderivatives 3 and 5 . 相似文献
13.
Latifeh Navidpour Mohsen Amini Abbas Shafiee 《Journal of heterocyclic chemistry》2007,44(6):1323-1331
A new series of 3‐alkylthio‐4,5‐diaryl‐4H‐1,2,4‐triazoles having a SO2NH2 substituent in the para‐position on one of the aryl rings ( 19/25 ) were prepared starting from the appropriate benzoic acid hydrazides ( 15/21 ). Reaction of the corresponding hydrazides with the appropriate isothiocyanates yielded 16/22 , which were cyclized in basic media to give 4,5‐diaryl‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thiones 17/23 . Alkylation of 17/23 afforded the alkylthio compounds 18/24 . Final debenzylation was achieved with concentrated sulfuric acid to give the target sulfonamides 19/25 . 相似文献
14.
The course of microwave assisted or conventional thermal intramolecular heterocyclization of the title compounds has been found to be dependent on the length of the alkanediyl chain. While 1,3‐propanediyl‐bisthioureas 5a‐c gave both 2‐thioxoperhydropyrimidine‐1‐carbothioamides 8a‐c and 8‐amino‐3,4,5,6‐tetrahydro‐1,3,7‐thiadiazocine‐2‐thiones 10a‐c , thermolysis of 1,4‐butanediyl‐bisthioureas 6a‐c and 1,6‐hexanediyl‐bisthioureas 7a‐c under the same conditions gave solely 9‐amino‐4,5,6,7‐tetrahydro‐1,3,8‐thiadiazonine‐2‐thiones 11a‐c and 11‐amino‐1‐thia‐3,10‐diazacycloundec‐10‐ene‐2‐thiones 12a‐c , respectively. Symmetric N,N′‐diorganylthioureas 4a‐c were formed in all cases as minor byproducts. 相似文献
15.
A novel versatile one‐pot oxidative deformylation approach has been developed to synthesize 4‐chloro‐2‐phenylquinolines and 4‐chloro‐2‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)quinolines from the corresponding N‐formyldihydroquinolines. 相似文献
16.
Malek Taher Maghsoodlou Nourollah Hazeri Sayyed Mostafa Habibi Khorassani Ghasem Marandi Mahmoud Nassiri 《Journal of heterocyclic chemistry》2006,43(2):481-484
The 1:1 intermediate generated by the addition of alkyl and aryl isocyanides to dialkyl acetylenedicarboxylate is trapped by 1,8‐diazafloren‐9‐one to yield iminolactones in good yields. 相似文献
17.
Yi‐Feng Wang Wei‐Min Liu You‐Quan Zhu Xiao‐Mao Zou Fang‐Zhong Hu Hua‐Zheng Yang 《Journal of heterocyclic chemistry》2006,43(5):1275-1280
A series of novel 6,7,8,9‐tetrahydro‐2‐(2‐aryloxypyrimidin‐4‐yl)‐2H‐[1,2,4]triazolo[4,3‐a]azepin‐3(5H)‐ones were designed and efficiently synthesized. Their structures were determined by IR, 13C and 1H NMR, mass spectroscopy, and elemental analysis. These compounds were screened for herbicidal activities against rape and barnyard grass. Compounds 5a‐5f and 5m exhibited moderate herbicidal activity against rape. In addition, the synthesis of the intermediate 1‐(azepan‐2‐ylidene)‐2‐(2‐chloropyrimidin‐4‐yl)‐hydrazine ( 3 ) was studied and the reason for the low yield in the initial procedure is discussed as well. 相似文献
18.
A. V. Karnik N. J. Malviya A. M. Kulkarni D. Jaimini B. L. Jadhav 《Journal of heterocyclic chemistry》2006,43(2):489-493
Chemoselective synthesis of novel hetero cyclopenta[b]chrysene derivatives, namely, 6‐Aryl‐2,2a‐dihydro‐naphtho[2′,1′‐5,6]pyrao[4,3‐e][1,2,4]triazolo[3,4‐b][1,3,4]thiadiazine ( 4a‐j ) under neutral condition has been described. These molecules exhibited good to excellent anti‐bacterial activities. 相似文献
19.
A concise and efficient synthetic approach to 3‐arylaminopyrroline‐2‐ones from anilines and β,γ‐unsaturated α‐ketoesters in boiling dichloromethane has been developed. This protocol possesses many advantages such as short reaction time, high isolated yields, and expanding substrate scopes. According to the isolated intermediates and controlled reactions, the reaction was tentatively proposed to involve the Michael addition/condensation and subsequent intramolecular cyclization. The structures of the title compounds were unambiguously confirmed by various spectral data such as X‐ray crystallographic analysis. 相似文献
20.
Ganesabaskaran Sivaprasad Radhakrishnan Sridhar Paramasivan T. Perumal 《Journal of heterocyclic chemistry》2006,43(2):389-394
A selective and easy method is described for the synthesis of 4,5‐dihydro‐2H‐benzo[g]indazoles and 8,9‐dihydro‐2H‐benzo[e]indazoles by the Vilsmeier‐Haack reaction of various tetralone phenylhydrazones under thermal and microwave irradiation conditions. 相似文献