F. Nawaz Khan

Synthesis of Some 3‐Substituted Isochromen‐1‐ones

Abstract An alternative method for the synthesis of 3‐substituted isocoumarins from homophthalic acid and ester is described.

SYNTHESIS OF O-SUBSTITUTED BENZOPHENONES BY GRIGNARD REACTION OF 3-SUBSTITUTED ISOCOUMARINS

ABSTRACT A series of o-substituted benzophenones was prepared by efficient method involving the 3-substituted isocoumarins and phenylmagnesium bromide. The reaction was completed in presence of anhydrous ether under dry ice-solvent bath in few hours with modest to good yields.Key words: Isocoumarins, diketones, aryl, phenyl magnesium bromide, ether, dry ice.e-mail: nawaz_f@yahoo.co.in. INTRODUCTION Synthetic and naturally occurring isocoumarins possess important biological properties. They are useful intermediates in the synthesis of a variety of carbocyclic and heterocyclic compounds 1-6 .In continuous of our interest in carbon-carbon bond formation reaction 7-12 ,the present paper presents an efficient method to synthesize o-substituted benzophenones (2) from 3-substitued isocoumarins (1) and phenyl magnesium bromide in presence of anhydrous ether under dry ice-solvent bath. Benzophenone and its derivatives are important intermediates in dyes, pharmaceutical and other chemical industries

SYNTHESIS OF 3 SUBSTITUTED ISOQUINOLIN-1-YL-2-(CYCLOALK-2-ENYLIDENE) HYDRAZINES AND THEIR ANTIMICROBIAL PROPERTIES

New hydrazine derivatives were synthesized via reaction between 1, 3 cyclic diketones and hydrazinoisoquinoline derivatives. The reaction proceeded smoothly in ethanol under reflux temperature and furnished products in excellent yields (76–87%). The products have been purified and fully characterized by spectroscopy techniques. The compounds 8a-c showed good bacterial inhibition against Bacillus cerus and 8d-f showed good antifungal activity against Candida albicans.

Evaluation of intermolecular interactions in thioisocoumarin derivatives: the role of the sulfur atom in generating packing motifs

Five derivatives of thioisocoumarin bearing aromatic and nonaromatic ring systems have been synthesized and characterized to unravel the importance of interactions due to the presence of a sulfur atom in generating packing motifs in the crystalline state. Apart from the well characterized interactions like C–H⋯S, a CS⋯π interaction is found in one of the case studies. The importance of such interactions in crystal structure packing along with routine C–H⋯π and π⋯π interactions is examined in the context of overall stability in the molecular assembly. The CS⋯π interactions in comparison to CO⋯π interactions have been analyzed using the Cambridge Structural Database (CSD).

3-Butyl-1H-isochromen-1-one

In the title compound, C13H14O2, a derivative of isocoumarin, the packing is stabilized by intermolecular C-H center dot center dot center dot O interactions.

2-Chloro-3-hydroxy-methyl-6-methoxy-quinoline.

All the non-H atoms of the title compound, C11H10ClNO2, are roughly coplanar (r.m.s. deviation = 0.058 Å). In the crystal, adjacent molecules are linked by an O—H⋯N hydrogen bond, generating chains running along the a axis.

Characterisation of novel pH indicator of natural dye Oldenlandia umbellata L.

Oldenlandia umbellata L., commonly known as ‘chay root’, belongs to the family Rubiaceae and is one of the unexplored dye-yielding plants. The roots from this plant are the sources of red dye. Extraction protocol and dye characterisation have not been completely studied so far in this plant. Hence, in this article we have used UV spectrophotometry, thin layer chromatography, GC-MS, high-performance liquid chromatography and NMR to identify the five major colouring compounds, including 1,2,3-trimethoxyanthraquinone, 1,3-dimethoxy-2-hydroxyanthraquinone, 1,2-dimethoxyanthraquinone, 1-methoxy-2-hydroxyanthraquinone and 1,2-dihydroxyanthraquinone. It showed application feasibility as a new pH indicator.

Synthesis of Diversified Thioethers,1-Aroylalkylisoquinolin-1-yl Thioethers, by Electrophilic S-Alkylation of 3-Phenyl Isoquinoline-1(2H)-thione

A mild and efficient method for the synthesis of thioethers has been developed. The 3-phenylisoquinoline-1(2H)-thione underwent S-alkylation to afford structurally diverse sulfides in high yield.

SYNTHESIS AND FREE RADICAL SCAVENGING PROPERTY OF SOME QUINOLINE DERIVATIVES

In the present work synthesis of 2-chloroquinoline-3-carbaldehydes (1a-g), 2-chloro-3-(1, 3-dioxolan-2-yl)quinolines (2a-g) and antioxidant activity using the DPPH assays is reported. The results showed that the compounds 1b, 1c, 2b, 2e, 2f possessed 84.65 to 85.75 % radical scavenging activity where as compound 1g showing 92.96% radical scavenging activity. due to high contents of certain phenolic compounds in plant-derived foods. Recently, phytochemicals and their effects on human health have been intensively studied. In particular, a search for antioxidants 3 , hypoglycemic agents 4 , and anticancer agents 5 in vegetables, fruits, tea, spices and medicinal herbs has attracted great attention. Naturally occurring plant phenolics include several groups of compounds that have health promoting properties. Phenolics may act as antioxidants, thereby reducing the risk of atherosclerosis and coronary heart disease, which can be caused by oxidation of low-density lipoproteins. They also may protect against some forms of cancer 6 . Quinoline moiety is mostly present in a medicinal plant whose tubers possesses cardiovascular, anti-inflammatory and antiparasitic effects and has been used for the treatment of hepatitis, rheumatism and diarrhea 7 . A solution of 2-chloroquinoline-3-carbaldehydes 1 (10 mmol) in benzene (50 mL) containing ethylene glycol (1.78 g, 1.6 mL, 28.5 mmol) and a crystal of toluene-p-sulfonic acid was heated under reflux for 5 hours using a Dean-Stark water separator until no more water collected in the side arm. The cooled solution was treated with saturated aqueous sodium carbonate (50 mL), Benzene layer separated, dried and evaporated giving 2 which was recrystallised from petroleum ether gave a yellowish white solid. The product was characterized by NMR, GCMS techniques. Similar proce- dures were followed for the synthesis of other quinoline derivatives 2a-g and Table 1. The spectral data of the compounds 1(a-g) & 2(a-g) is given below. 2-Chloroquinoline-3-carbaldehyde

Synthesis of Some New 2,4-Disubstituted Hydrazinothiazoles and 2,5-Disubstituted Thiazolidinones

A series of hydrazinothiazoles has been synthesized by the condensation of thiosemicarbazones and α-bromoketones. Similarly the hydrazinothiazolidiones were prepared by the condensation of thiosemicarbazone and α-bromoesters. The newly synthesized compounds were characterized by NMR and LCMS studies.