Search results for "Zole"
showing 10 items of 2482 documents
Heterocyclic rearrangements.N,N-diphenylhydrazones, oximes andO-methyloximes of 3-benzoyl-5-phenyl-1,2,4-oxadiazole
1985
The behaviour of (E)- and (Z)-N,N-diphenylhydrazones and O-Methyloximes of 3-benzoyl-5-phenyl-1,2,4-oxadiazole has been studied. When refluxed in benzene, or in dioxane-water (1:1), the (Z)-N,N-diphenylhydrazone 8Z gave the indazole 11 or the substituted semicarbazide 12, respectively. The O-methyloxime 14Z did not give any rearrangement. A criticism of the oximation reaction of 3-benzoyl-5-phenyl-1,2,4-oxadiazole is also reported.
Imidazolsynthesen, Mitt. Synthese α-substituierter 4(5)-Methoxymethyl-5(4)-methyl-imidazole
1977
Methoxymercurierung der α,β-ungesattigten Ketone 1 ergibt α-Acetoxymercuri-β-methoxy-ketone 2, die direkt zu α-Brom-β-methoxy-ketonen 3 bromo- demercuriert werden. Cyclisierung von 3 mit Formamidinacetat in flussigem Ammoniak fuhrt zu α-substituierten 4(5)-Methoxy-methyl-5(4)-methyl-imidazolen 4, deren Struktur 13C-NMR-spektroskopisch gesichert ist. Synthesis of α-Substituted 4(5)-Methoxymethyl-5(4)-methylimidazoles Methoxymercuration of the α,β-unsaturated ketones 1 produces the α-acetoxymercury-β-methoxyketones 2, which are bromo-demercurised without isolation to give the α-bromo-β-methoxyketones 3. Cyclisation of 3 with formamidine acetate in liquid ammonia leads to α-substituted 4(5)-me…
Neue Diels-Alder-Reaktionen von 1-Methylpyrano[3,4-b]indol-3(9H)-on mit cyclischen CC-Dienophilen: ein einfacher Zugang zu [b]anellierten Carbazol-De…
1988
1-Methylpyrano[3,4-b]indol-3(9H)-on (1) reagiert als synthetisches Aquivalent von Indolo-2,3-chinodimethan mit Arin, p-Benzochinon und p-Naphthochinon zu neuen [b]anellierten Carbazol-Derivaten. Durch das Reaktionsmedium bedingt lassen sich bei der Cycloaddition von 1 mit Arin zugleich auch mononitrierte Carbazole isolieren. New Diels-Alder Reactions of 1-Methylpyrano[3,4-b]indol-3(9H)-one with Cyclic CC-Dienophiles: A Simple Way to [b]Annulated Carbazole Derivatives. 1-Methylpyrano[3,4-b]indol-3-(9H)-one (1) reacts as synthetic equivalent of indolo-2,3-quinodimethane with benzyne, p-benzoquinone, and p-naphthoquinone to give new [b]annulated carbazole derivatives. In the Diels-Alder reacti…
Eine neue Synthese von Imidazolderivaten. 1. Mitt.: Zur Darstellung 2-substituierter Imidazol-4-alkohole
1973
2-Substituierte Imidazol-4-alkohole (3) lassen sich aus Alkyl- oder Aryliminoestern (1) und α-Hydroxyketonen (2) in flussigem Ammoniak unter Druck mit guten Ausbeuten darstellen. A New Synthesis of Imidazole Derivatives The 2-substituted imidazole-4-alcohols (3) are obtained from alkyl- or aryl-iminoesters (1) and α-hydroxy-ketones (2) in liquid ammonia under pressure in good yields.
Conjugated Compounds Based on Vinylthiazole Units
2007
Conjugated oligomers attract increasing attention because of their interesting properties in materials science [1]. Moreover, they are model compounds for conjugated polymers. Molecules polarized by electronic effects, in particular push-pull systems having terminal donor-acceptor substitution represent a special class of such oligomers [2]. Their major applications are in the field of nonlinear optics (NLO), twophoton absorption (TPA), two-photon induced fluorescence (TPIF), and photorefractive materials (PR). Fig. 1 illustrates known 2,5-thienylenevinylenes with zwitterionic resonance structures 1 (D = NR2; A = NO2, CHO, SO2R; n = 1, 2) [3, 4]. The corresponding compounds 2 with thiazole …
Synthesis of 4-amino-5-fluoropyrimidines and 5-amino-4-fluoropyrazoles from a β-fluoroenolate salt
2020
A synthesis of fluorinated pyrimidines under mild conditions from amidine hydrochlorides and the recently described potassium 2-cyano-2-fluoroethenolate was developed. A broad substrate scope was tested and mostly excellent yields were obtained. The synthesis of fluorinated aminopyrazoles from the same fluorinated precursor could be demonstrated but proceeded with lower efficiency.
Cu(II), Ni(II) and Zn(II) mononuclear building blocks based on new polynucleating azomethine ligand : Synthesis and characterization
2017
Five new mononuclear complexes formed by the polynucleating ligand 2-[1-(3,5-dimethyl)pyrazolyl]-2-hydroxyimino-N′-[1-(2-pyridyl)ethylidene]acetohydrazide (HL): [Ni(L)(HL)]ClO4·2CH3OH (1), [Ni(L)2]·CH3OH (2), [Zn(L)(HL)]ClO4·2CH3OH (3), [Zn(L)2]·CH3OH (4) and [Cu(L)2]·CH3OH (5) were synthesized and characterized by elemental analysis, mass-spectrometry, IR-spectroscopy and X-ray analysis. The complexes reveal distorted octahedral N4O2 coordination arrangement formed by both protonated and deprotonated (1, 3) or two deprotonated ligand molecules (2, 4, 5). The presence of non-coordinated oxime and pyrazole groups resulted in the formation of extensive systems of hydrogen bonds in the crystal…
Susceptibility of Methyl 3-Amino-1H-pyrazole-5-carboxylate to Acylation
2009
Abstract In the search for a new method of synthesis of hybrid peptides with aminopyrazole carboxylic acid, we tried to force selective acylation at the aromatic amino group instead of at the ring nitrogen atom with fairly gentle acylating agents. The acylating agents used were acid anhydrides: acetic anhydride, tert-butyl pyrocarbonate, and 2-(2-methoxyethoxy)ethoxyacetic acid/dicyclohexylcarbodiimide. We succceded in acylation at this amino group with almost none at the ring nitrogen atom. Sometimes, however, acylation in small quantities at the ring nitrogen atom was observed as a by-product. To remove this by-product, imidazole was used. Thus, we were able to obtain the hybrid peptides …
Crystal structure of C-2-benzo-thia-zole-N-methyl-nitrone.
2015
The molecule of the title compound {systematic name:N-[(benzothiazol-2-yl)methylidene]methylamineN-oxide}, C9H8N2OS, is close to planar [maximum deviation from the mean plane = 0.081 (2) Å], its conformation being stabilized by a strong intramolecular attractive S...O interaction [2.6977 (16) Å]. In the crystal, molecules are linked into centrosymmetric dimers by pairs of weak C—H...O hydrogen bonds.
Post-synthetic methods for functionalization of imidazole-fused porphyrins
2018
Several methods for the post-synthetic modification of imidazo[4,5-[Formula: see text]]porphyrins are reported. First, a synthetic approach to the isomeric difunctionalized porphyrins, containing two [Formula: see text]-fused 2-aryl-1[Formula: see text]-imidazole cycles at adjacent or opposite pyrrole rings of the macrocycle is developed. The core chemistry of this synthetic route is the transformation of 2-aryl-1[Formula: see text]-imidazo[4,5-[Formula: see text]]porphyrins into corresponding imidazodioxochlorins followed by Debus–Radziszewski condensation with aromatic aldehyde. Next, 2-(4-bromophenyl)-1[Formula: see text]-imidazo[4,5-[Formula: see text]]-5,10,15,20-tetramesitylporphyrin…