Search results for "medicinal"
showing 10 items of 2966 documents
Alkyl and diether bridged N,N,N′,N′-tetra(2-hydroxybenzyl)diamines: effects of hydrogen bonding on structure and solubility
2012
A solvent-free one-step method has been used to prepare two N,N,N′,N′-tetra(2-hydroxy-3,5-dimethylbenzyl)diaminoalkanes containing a long n-alkyl bridge (6 and 8 CH2 groups between N-atoms). In addition, three novel N,N,N′,N′-tetra(2-hydroxy-5-alkyl-3-alkylbenzyl)-diaminoalkane-ethers (alkyl = methyl or t-butyl) have been prepared using the same method. The compounds were studied in the solid state using single crystal X-ray diffraction and their solubility was studied using UV/Vis spectroscopy. In the solid state, hydrogen bonding plays a key role in controlling the crystal packing and conformations of the molecules, thus affecting the solubility and properties of the compounds.
rac-(3E,3aR,6aR)-3-(Hydroxymethylene)-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one
2007
The crystal structure of the title compound, C8H8O3, was determined in the course of our studies of the synthesis of cyclopenta[1,2-b]furan-4-one derivatives. The title compound has two chiral C atoms and was obtained as a racemic mixture. It was found to possess a vinylogous acid group with an E configuration at the double bond. The compound exists in the hydroxymethylene and not in the tautomeric carbaldehyde form. The asymmetric unit consists of two molecules.
Phytochemical constituents and chemosystematic significance of Pulicaria jaubertii E.Gamal-Eldin (Asteraceae)
2018
Abstract The chemical characterization of methylene chloride/methanol (1:1) extract of the air-dried whole medicinal plant, Pulicaria jaubertii E. Gamal-Eldin, led to isolation and identification of two new hydroquinone compounds; 2-(2-acetoxy propyl), 5-methyl hydroquinone (1) and 2-(2-hydroxy propyl), 5-methyl hydroquinone-4-O-β-D-glucopyranoside (2), four known flavonols (3-6) and 7 known dihydroflavonols (7-13). The structures were established depending upon comprehensive analysis of the NMR, IR and HR/EI-MS data. Herein, compounds 6, and 10-13 were isolated for the first time from this plant. The chemotaxonomic significance of the isolated flavonoids from P. jaubertii comparing with th…
Saponin with antibacterial activity from the roots of Albizia adianthifolia
2019
AbstractAn unprecedented saponin is being reported herein together with five known compounds from the methanol extract of the roots of Albizia adianthifolia. The metabolites were obtained over repe...
One-Pot Oxidative C–H Activation/Aza-Prins-Type Reaction of Tertiary Alkynylamines: A Counter Ion-Induced Iminium Ion–Alkyne Cyclization
2021
Herein, the design and development of a new one-pot and metal-free oxidative C-H activation/aza-Prins type cyclization of alkynylamines is reported. The scope of this method was demonstrated by the preparation of ten new pyrido[2,1-a]isoquinolines in moderate to high yields (38-92%). Furthermore, a mechanistic proposal for the alkyne aza-Prins cyclization is described based on DFT calculations.
An alternative route to 2H-naphtho[1,2-b]thiete and its cycloaddition products
1998
2-(1H-Benzotriazol-1-ylmethyl)-1-naphthalenol (1) can be transformed in high yields to the corresponding thiol 4. Flash vacuum pyrolysis of 4 leads to 2H-naphtho[1,2-b]thiete (5). The benzotriazolyl group proved to be a good leaving group; however, a subsequent nitrogen extrusion takes place under flash vacuum pyrolysis conditions and cyclopentadienecarbonitriles 6a,b are formed by a ring contraction (Scheme 1). Cycloaddition reactions of 5 and dienophiles or heterodienophiles yield the naphtho-condensed sulfur heterocycles 8, 10, 12 and 14 (Scheme 2).
Cycloaddition reactions of benzothiete with azomethines
1986
Obtention de diaryl-2,3 dihydro-3,4 benzothiazines-1,3 (70%) via la cycloaddition de la thiobenzoquinone methode-1,2 (obtenue par scission thermique du benzothiete) et d'arylimines de benzaldehydes. Obtention egalement de 10% du dimere (dibenzo [b, f] dithiocinne-1,5)
ChemInform Abstract: C-C versus C-N Annulation Reactions of 2-Alkyl-2-oxazolines and 2-Alkyl-2-thiazolines: A Simple Synthesis of Novel 3-Aminoindene…
2010
The effect of various aromatic and aliphatic dielectrophiles on the lithium azaenolates of 2-alkyl-2-oxazolines and 2-alkyl-2-thiazolines has been examined. This effect varies greatly, depending on the nature of the dielectrophile used. 3-Aminoindene (3) and 3-alkylidenephthalimidine (4−5) derivatives were formed as a result of the reactions with dielectrophiles derived from ortho-substituted benzonitriles. Similarly, 2-alkylidenepyrrolidine (7) and 2-alkylidenepiperidine (8) derivatives were obtained in high yields from 2-alkyl-2-oxazolines or 2-alkyl-2-thiazolines and aliphatic dielectrophiles derived from ω-haloalkyldiphenylacetonitrile. C−C versus C−N annulation reactions are discussed.
ChemInform Abstract: LEAD TETRAACETATE OXIDATION OF PHENYLHYDRAZONES OF 3-BENZOYLAZOLES. SYNTHESIS OF AZOACETATES AND THEIR CONVERSION INTO INDAZOLES
1985
Lead tetraacetate (LTA) oxidation of (E)- and (Z)-phenylhydrazones of 3-benzoyl-5-phenyl-1,2,4-oxadiazole, 3-benzoyl-5-phenylisoxazole, and 3-benzoyl-4-methyl-1,2,5-oxadiazole has been studied. Conversion of azoacetate products into 3-(azol-3-yl)-substituted indazoles has been achieved by reacting them with aluminium chloride in benzene at room temperature.
ChemInform Abstract: Palladium-Catalyzed Synthesis of Mono- and Diphosphorylated 1,10-Phenanthrolines.
2013
A general protocol for the coupling of mono- and dihalo-1,10-phenanthrolines with diethyl phosphite is reported. This reaction proceeds smoothly in the presence of a Pd(OAc)2/dppf catalytic system and triethylamine as a base.