Safdar Hayat

N-Alkylation of anilines, carboxamides and several nitrogen heterocycles using CsF–Celite/alkyl halides/CH3CN combination

It has been found that the N-alkylation of aniline, carboxamides and heterocyclic compounds bearing an acidic hydrogen atom attached to nitrogen can be accomplished with alkyl halides in acetonitrile and cesium fluoride–celite employed as a solid base. In this manner, pyrrole, indole, pyrazole, imidazole, benzimidazole, carbazole, phthalimide, indazole, indoline, 2-pyrrolidinone, piperidine and 1,2,4-triazole can be successfully alkylated. The procedure is convenient, efficient and generally gives rise to the N-alkylated product exclusively.

Synthesis and In Vitro Leishmanicidal Activity of Some Hydrazides and Their Analogues

Twenty-one hydrazides were synthesized by treating different esters with hydrazine hydrate. Substituted hydrazides were obtained by treating hydrazides with alkyl/aryl/acyl halides. Some of these compounds exhibit potential in vitro leishmanicidal activity. The structures of all the synthesized compounds were confirmed by spectroscopic analysis.

An expedient esterification of aromatic carboxylic acids using sodium bromate and sodium hydrogen sulfite

Abstract Treatment of aromatic carboxylic acids and substituted toluenes with a mixture of sodium bromate and sodium hydrogen sulfite in a two-phase system gave the corresponding esters in good yield. The intermediate α-brominated toluene was formed by the in situ generated hypobromous acid. The α-bromotoluene underwent an intermolecular nucleophilic substitution reaction with aromatic carboxylic acids present in the reaction mixture to afford the corresponding esters.

An improved method for the synthesis of γ-lactones using sodium bromate and sodium hydrogen sulfite

o-Alkylbenzenecarboxylic acids are treated with a sodium bromate and sodium hydrogen sulfite reagent under a two-phase system using ethyl acetate as solvent, under mild conditions to give the corresponding cyclized phthalides in moderate to satisfactory yield. Intermediately the α-brominated alkylbenzenecarboxylic acids are formed by the in situ generated hypobromous acid. These α-brominated acids undergo an intramolecular nucleophilic substitution reaction to afford the corresponding γ-lactones.

Spatozoate and varninasterol from the brown alga Spatoglossum variabile

Two new compounds, spatozoate and varninasterol were isolated from Spatoglossum variabile. Four known compounds, fucosterol, cholesta-5-ene-23-yne-3β-ol, apiole and nothoapiole were also isolated for the first time from the methanolic extracts of this alga. The structure elucidation of the new compounds were carried out with the help of modern spectroscopic techniques.

An alternative method for the synthesis of γ-lactones by using cesium fluoride-celite/acetonitrile combination

Abstract A variety of 2-(1-bromoalkyl) benzoic acids 4 undergo intramolecular nucleophilic substitution reaction when treated with a CsF-Celite as solid base in acetonitrile under reflux condition to give the corresponding cyclized phthalides in moderate to very good yield. These 2-(1-bromoalkyl) benzoic acids 4 are formed by the α-bromination of 2-alkylbenzoic acids 3 using N-bromosuccinimide and a catalytic amount of α,α′-azoisobutyronitrile in carbon tetrachloride under reflux.

Synthesis and Biological Screening of 7-Hydroxy-4-Methyl-2 H -Chromen-2-One, 7-Hydroxy-4,5-Dimethyl-2 H -Chromen-2-One and their Some Derivatives

7-Hydroxy-4-methyl-2 H -chromen-2-one (2) , 7-hydroxy-4,5-dimethyl-2 H -chromen-2-one (15) and their some derivatives were synthesized for exploring selected biological screening. The compounds 9 and 13 had shown high degree of cytotoxic activity. Three compound 9 , 10 and 13 showed high degree of bactericidal activity amongst the present series.

An Alternative Method for the Highly Selective Iodination of Alcohols Using a CsI/BF3·Et2O System

Abstract A variety of allylic and benzylic alcohols have been converted into the corresponding iodides using cesium iodide (CsI) in the presence of boron trifluoride etherate (BF3·Et2O) in acetonitrile under mild conditions.

Two New Triterpenes from Fern Adiantum incisum

Two new triterpenes, adininaneone (1) and adininaonol (2) were isolated from Adiantum incisum. Three known triterpenes, adiantone (3), isoadiantone (4) and 23-hydroxyfernene (5) were also isolated for the first time from the methanolic extracts of A. insicum. The structures were elucidated with the help of modern spectroscopic techniques.

Synthesis and Bioactivities of Naturally Occurring Anthraquinones: Isochrysophanol, Isozyganein, ω-Hydroxyisochrysophanol and Morindaparvin

Isochrysophanol, isozyganein, ω-hydroxyisochrysophanol, and morindaparvin are naturally occurring substituted anthraquinones. We report the synthesis of these compounds as well as selected biological activities.