Academia.edu no longer supports Internet Explorer.
To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser.
2008 •
Organic & Biomolecular Chemistry
A versatile synthesis of pyrazolo[3,4-c]isoquinoline derivatives by reaction of 4-aryl-5-aminopyrazoles with aryl/heteroaryl aldehydes: the effect of the heterocycle on the reaction pathwaysTetrahedron Letters
Benzo-separated pyrazolopyrimidines: Expeditious syntheses of [3,4-g]-and [3,4-h]-linked pyrazoloquinazolinones1981 •
European Journal of Organic Chemistry
Three‐Component (Domino) Reaction Affording Substituted Pyrroloquinazolines: Cyclization Regioselectivity and Stereoselectivity2013 •
The cyclization involving 2‐(aminomethyl)aniline, methyl 3,3,3‐trifluoropyruvate, and various oxo compound afforded linearly annulated pyrroloquinazolines, for example, (2R*,3aS*)‐2‐hydroxy‐3a‐phenyl‐2‐trifluoromethyl‐3,3a,4,9‐tetrahydropyrrolo[2,1‐b]quinazolin‐1(2H)‐one (cis‐8), as the major product, possessing the skeleton of the alkaloids of the vasicine group, along with angularly annulated products, for example, (2S*,3aR*)‐2‐hydroxy‐3a‐phenyl‐2‐trifluoromethyl‐3,3a,4,5‐tetrahydropyrrolo[1,2‐a]quinazolin‐1(2H)‐one(cis‐18). The effects of the nature of the oxo compound and the temperature on the ratio of the linear and angular cyclization products, as well as the diastereoselectivity of the product formation, were studied, with an increase in temperature leading to improved selectivity. Some of the linear pyrroloquinazolines were stereoselectively didehydrogenated at the quinazoline ring by the trifluoropyruvate.
Molecular Diversity
One-pot microwave assisted preparation of pyrazoloquinazolinone libraries2003 •
The novel solution phase synthesis of an array of biologically relevant pyrazoloquinazolinones in a simple microwave driven, one pot procedure is described. Transformations are carried out in good to excellent yield by condensation of α-cyano-ketones and 2-hydrazino-benzoic acids. Subsequent microwave irradiation affords pyrazoloquinazolinones with six points of potential diversification. The protocol described represents a very attractive solution phase procedure for the rapid generation of arrays of such functionalized cores, further demonstrating the growing importance of economic al chemistries that enable complexity to the genered in this leading arena.
Journal of Heterocyclic Chemistry
Friedländer condensation of 5-aminopyrazole-4-carbaldehydes with reactive α-methylene ketones: Synthesis of pyrazolo[3,4- b ]pyridines2005 •
A series of 1,3,6-trisubstituted and 1,3,5,6-tetrasubstituted pyrazolo[3,4-b]pyridines 5 has been synthesized by Friedlander condensation of 5-arninopyrazole-4-carbaldehydes 3 with α-methylene ketones such as acetone (4a) or acetophenones 4b-f with potassium hydroxide as basic catalyst. Condensation of 5-aminopyrazole-4-carbaldehydes 3 and unsymmetric dialkylketones 6 yielded mixtures of isomeric pyra-zolo[3,4-b]pyridine derivatives 7 and 8. Condensation of 5-aminopyrazole-4-carbaldehydes 3 with CH-acidic acylacetonitriles 9 and acylacetates 11 with piperidine as basic catalyst yielded pyrazolo[3,4-b]pyri-dine-5-carbonitriles 10 and pyrazolo[3,4-b]pyridine-5-carboxylates 12; with diethyl malonate 13 as CH-acidic component, pyrazolo[3,4-b]pyridin-6-ones 14 were obtained.
Australian Journal of Chemistry
Microwave-Accelerated Solvent- and Catalyst-Free Synthesis of 4-Aminoaryl/alkyl-7-chloroquinolines and 2-Aminoaryl/alkylbenzothiazoles2007 •
An efficient synthesis of 4-aminoaryl/alkyl-7-chloroquinolines and 2-aminoaryl/alkylbenzothiazoles has been developed by microwave-accelerated regioselective aromatic nucleophilic substitution of 4,7-dichloroquinoline and 2-chlorobenzothiazole with aromatic and aliphatic amines under solvent-free conditions in the absence of any added protic or Lewis acid catalyst. Chemoselective reaction with the amino group in preference to the phenolic hydroxy group was observed. Thus, the treatment of 4,7-dichloroquinoline (1 equiv.) with a mixture of aniline (2 equiv.) and phenol (2 equiv.) afforded exclusive formation of 4-aminophenyl-7-chloroquinoline. When 4,7-dichloroquinoline (1 equiv.) was separately treated with 2-aminophenol (2 equiv.) and 4-aminophenol (2 equiv.), 4-(2′-hydroxyphenyl)-7-chloroquinoline and 4-(4′-hydroxyphenyl)-7-chloroquinoline, respectively, were formed.
2024 •
Journal of Analytical Sciences, Methods and Instrumentation
Developed New Procedure for Low Concentrations of Hydrazine Determination by Spectrophotometry: Hydrazine-Potassium Permanganate System2012 •
Microorganisms
In Vitro and In Vivo Study of Combined Effect of Some Algerian Medicinal Plants and Probiotics against Helicobacter pylori2023 •
Microporous and Mesoporous Materials
Operando Raman-mass spectrometry investigation of hydrogen release by thermolysis of ammonia borane confined in mesoporous materials2016 •
International Journal of Molecular Sciences
Ketogenic Diet in Alzheimer’s Disease2019 •
Proceedings of the Royal Society B: Biological Sciences
Pest defences under weak selection exert a limited influence on the evolution of height growth and drought avoidance in marginal pine populations