排序方式: 共有46条查询结果,搜索用时 15 毫秒
1.
Bombek S Lenarsic R Kocevar M Saint-Jalmes L Desmurs JR Polanc S 《Chemical communications (Cambridge, England)》2002,(14):1494-1495
An electrophilic amination of halogenated phenols with diisopropyl diazenedicarboxylate in the presence of ZrCl4 as a Lewis acid, accompanied by a halogen migration, was demonstrated for the first time; the fluorine, chlorine, bromine, or iodine atom migrated during the amination process under mild reaction conditions. 相似文献
2.
2-Azidopyrido[1,2-a]pyrimidin-4-one can exit only in the azido form and undergoes cyclo-addition reaction with 1,3-dicarbonyl compounds to form 1,2,3-triazole derivatives. Under the influence of bases or hydrochloric acid the carbonyl group is attacked with subsequent opening of the pyrimidine ring. This causes an immediate cyclization of the azide group to give a tetrazolo derivative. In a similar way a triazole ring can be formed from the appropriate hydrazino derivatives of pyrido[1,2-a]pyrimidin-4-one. 相似文献
3.
S. Polanc B. Stanovnik M. Tišler M. Jurgec 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):247-248
Abstract The experimental evidence concerning the nitration of 1,2,3-benzothiadiazole is conflicting. We have found that 4-nitro- and 7-nitro-1,2,3-benzothiadiazole are the major products, while from 6-chloro-1,2,3-benzothiazole 6-chloro-7-nitro-benzothiadiazole (I) was formed as the only product. 相似文献
4.
Jeselnik M Varma RS Polanc S Kocevar M 《Chemical communications (Cambridge, England)》2001,(18):1716-1717
The reaction of neat 5- or 8-oxobenzopyran-2(1H)-ones, 1-3, with a variety of aromatic and heteroaromatic hydrazines, 4, is remarkably accelerated upon irradiation in a household microwave oven in the absence of any catalyst, solid support or solvent thus providing an environmentally friendly route to several heterocyclic hydrazones. 相似文献
5.
Amadej Juranovi?Krištof Kranjc Franc PerdihSlovenko Polanc Marijan Ko?evar 《Tetrahedron》2011,67(19):3490-3500
A comparative study of the reaction pathway of the cycloaddition of various vinyl-containing dienophiles on a set of substituted 3-acylamino-2H-pyran-2-ones under microwave-assisted and high-pressure conditions is presented. In the course of the reaction both the intermediate products, i.e., the 2-oxabicyclo[2.2.2]oct-5-ene (the exo/endo selectivity depended upon the dienophile) and the alkoxycyclohexadiene systems, were isolated and comprehensively characterized; this included X-ray diffraction analyses. The role of the base (DABCO) as an organocatalyst was further elucidated. 相似文献
6.
Polonca Trebe Boris Recelj Marijan Ko
evar Slovenko Polanc 《Journal of heterocyclic chemistry》1997,34(4):1247-1250
A simple, highly selective transformation of 5,6,7,8-tetrahydro-2H-1-benzopyran-2,5-diones 1–3 and 14 with some phenylhydrazines and heterocyclic hydrazines to 5-hydrazono-2H-1-benzopyran-2-ones 4–12 and 15–16 is described. Under more severe conditions the hydrazonoquinoline derivative 17 was obtained from the benzopyran derivative 3 and Phenylhydrazine. 相似文献
7.
4-Alkoxy substituted 1,3,2-dioxaborinanes 1, readily available from β-keto esters, undergo substitution reactions under mild reaction conditions with primary and secondary amines, deriving the 4-alkylamino analogue 2. Reactions of 1 with substituted phenylhydrazines gave the corresponding hydrazones, or pyrazolones, and 5-alkoxy-1H-pyrazoles as a mixture of products. 相似文献
8.
Cis-[Cr(en)2F2]ClO4 · NaClO4 · H2O (en = 1,2-diaminoethane) was obtained as the red crystalline product from the saturated solutions of both NaClO4 and cis-[Cr(en)2F2]ClO4 in water. The compound crystallizes in the monoclinic P21/n (No.14) space group with a = 9.540(2), b = 11.840(2); c = 14.659(3) Å, β = 95.02(1)°, Z = 4. The unit cell of the racemic crystal contains cis-[Cr(en)2F2]+ in the Λλλ and Δδδ enantiometric forms, Na+, ClO4?, and lattice H2O. Cr has octahedral coordination. Cr? F and Cr? N bonds are 1.868(4), 1.887(5) and from 2.067(2) to 2.100(8) Å. Mean Cl? O bond is 1.38 Å. Na+ ions are in the distorted octahedral environment. Infrared spectrum confirms the presence of the lattice H2O and proves the cis structure of [Cr(en)2F2]+. 相似文献
9.
K. Babi
S. Molan S. Polanc B. Stanovnik J. Stres-Brato M. Tiler B. Ver
ek 《Journal of heterocyclic chemistry》1976,13(3):487-490
The formation of 3-oxides of triazolopyridine, triazolopyridazine and triazolopyrazine was investigated. The corresponding 3-oxides were obtained by oxidative cyclization of 2-hydroxy-iminomethyleneaminoazines and some transformations are described. 相似文献
10.
L. Kramberger P. Loren
ak S. Polanc B. Ver
ek B. Stanovnik M. Tiler F. Povaanec 《Journal of heterocyclic chemistry》1975,12(2):337-342
The formation of heterocyclic thioamides from alkylpyridines, heteroaromatic amines and sulfur was investigated. Oxidative cyclization of these thioamides afforded the corresponding thiazoloazines. Attempted thiation of some hydrazones gave triazolopyridines and some examples of direct thiation of heterocycles are given. 相似文献