Indian Journal of Chemistry

Sect. B: Organic Chemistry including Medicinal Chemistry

VOL. 46B

NUMBER 9

September 2007

CONTENTS

Rapid Communication

1455

Bismuth (III) nitrate pentahydrate – An efficient catalyst for the synthesis of bis(indolyl)methanes under mild conditions

Bismuth (III) nitrate pentahydrate BN has been used successfully for the electrophilic condensation of indole with a wide range of aldehydes to obtain bis(indolyl)methanes at ambient temperature. The methodology has the advantages of usage of inexpensive catalyst, short reaction time and mild reaction work up.

Deepak K Deodhar, Ramakrishna P Bhat & Shriniwas D Samant*

Papers

1459

A facile microwave assisted synthesis and antimicrobial activities of naturally occurring (E)-cinnamyl (E)-cinnamates and

(E)-aryl cinnamates

Benzaldehydes on reaction with phosphorane  and aldehydes with phosphorane  under microwave irradiation provide the (E)-cinnamyl (E)-cinnamates and (E)-aryl cinnamates respectively in high yield. The synthesized cinnamates  exhibit antibacterial and antifungal activity.

Rajesh P Mahajan, Ulhas K Patil &
Shamkant L Patil*

1466

Microwave irradiation accelerated rapid, efficient and high yield esterification of Boc-amino acid to Merrifield resin mediated by KF

A rapid and efficient procedure for the attachment of Boc-amino acid to Merrifield resin in the presence of potassium fluoride by flash heating under microwave irradiation has been described. Esterification rate acceleration and higher loadings are obtained significantly. Also, reaction times are reduced from the conventional 24 hr to 5-6 min duration under microwave irradiation.

Vommina V Suresh Babu*, Kantharaju &
G Chenna Krishna

1470

Studies in microwave mediated solvent-free synthesis of 5-aryl-2,3-diphenylpyrroles from 4-aryl-1,2-diphenyl-2-butene-1,4-diones

(i)                  NH₄⁺HCOO^-, MW 270W, 2 min, 46-66%.

H Surya Prakash Rao*, Bala Kishan Gorityala &
K Vasantham

1475

Synthesis of a new series of chiral tri and tetradentate ligands and their application in titanium-catalyzed pinacol coupling reaction

A Chatterjee & N N Joshi*

1483

Model study on the sequence specific stacking by chromophore of an anticancer drug, acridine carboxamide with base pairs of DNA

The stacking of various acridine carboxamide analogues (i.e carboxamide side chain at different positions) with AT and GC are studied. The variation of the interaction energies is thoroughly explored. Results support the preferential GC specificity of this drug.

Coloured Fig (5.5 cm)

 Stacked model of drug and GC base pair

Raghab Parajuli, Rajib Lochan Sarma,
Manas Lochan Das & C Medhi*

1495

1,3-Dipolar cycloadditions: part XIV — Highly selective cycloadditions of C,N-diaryl nitrones to diethyl arylmethylene malonates

Cycloaddition of nitrones to diethyl arylmethylene malonates occurred with very high selectivity to furnish 3,5-trans-2,3,5-triaryl-4,4-dicarbethoxy isoxazolidines. This is in contrast with the nitrone cycloadditions to other a ,b -conjugated carbonyl derivatives where two diastereoisomeric (and on occasion regioisomeric) cycloadducts are generally obtained.

A Banerji*, S Sengupta, A Nayak, P K Biswas,
B Bhattacharya, S Dasgupta (Mrs. Ray),
R Saha, Thierry Prangé & Alain Neuman

1501

Biocatalytic acylation studies on novel 3-aryl-3-hydroxymethyl-2,3-dihydro-4H-1-benzopyran-4-ones

A series of isoflavanone derivatives have been synthesized. Enzymatic acylation studies on these compounds using Candia antarctica lipase are described. Different enzymes, e.g,. Candia antarctica (CAL), Candia rugosa (CRL), porcine pancreatic (PPL), Amano PS and Amano PY have been screened in different solvents viz. toluene, tetrahydrofuran (THF) and diisopropylether (DIPE). In addition different acylating agents have also been screened.

Vijayendra Kumar, Rajesh Kumar,
Raunak,Poonam, Sunil K Sharma,
Ashok K Prasad, Ashok L Cholli, Carl E Olsen & Virinder S Parmar*

1511

Synthesis, characterization and spectral correlations in substituted styryl 6-methyl-2-naphthyl ketones

G  Thirunarayanan

1518

Exploratory studies towards AB-ring system of taxanes via intramolecular alkylation reaction. Formation of bicyclo[2.2.2]-octanones in preference to bicyclo[5.3.1]-undecanes

An intramolecular alkylation based approach is explored for the enantiospecific construction of AB-ring system of taxanes, which however leads only to bicyclo[2.2.2]-octanones.

A Srikrishna*, T Jagadeeswara Reddy &
P Praveen Kumar

1526

Rotational equilibria in boat conformations of N-acyl-r-2,c-6-di(2-hetero- aryl)piperidin-4-ones using  NMR spectra and semiempirical MO calculations

Four N-acyl-r-2,c-6-di(2-heteroaryl)piperidin-4-ones  have been found to exist in equilibrium between boat conformations B1 and B2 in solution and gaseous states

J C Thenmozhiyal, M Venkatraj*, S Ponnuswamy & R Jeyaraman

1537

Syntheses of 1,5-benzothiazepines: Part XXXIII—Syntheses and antimicrobial studies of 10-sub-stituted-6-(4-methoxyphenyl)-6H-6a,7-dihydro-7-(4-methoxyphenyl/3,4dimethoxyphenyl)[1]benzo-pyrano[3,4-c][1,5]benzothiazepines

Seema Pant, Priyanka Sharma, B S Sharma &
Umesh C Pant*

Notes

1545

An efficient, simple, one pot synthesis of dihydropyrimidine-2(1H)ones using phosphorus pentoxide

Phosphorus pentoxide has been found to be a mild and efficient reagent for synthesis of dihydropyrimidones and its corresponding thio-analogues in refluxing ethanol.

M B Deshmukh*, Prashant V Anbhule,
S D Jadhav, A R Mali, S S Jagtap &
S A Deshmukh

1549

Environmentally benign approach to imidazole 2-thiones

A green synthesis of some novel 1,4,5-triarylimidazole-2-thiones/1,3,4,5-tetraarylimidazole-2-thiones is described.  The reaction involves condensation of benzoin with various readily accessible N-substituted thioureas/N,N'-disubstituted thioureas under microwaves over recyclable inorganic solid support.

Mazaahir Kidwai*, Shuchi Kukreja,
Shweta Rastogi & Kavita Singhal

1554

Reactivity pattern of in situ generated tetraethylammoniun superoxide with some flavonoids

A number of flavonoids have been allowed to react under the mild reaction conditions of tetraethylammonium superoxide in dry dimethylformamide at room temperature. As an outcome, 3-hydroxyflavones 1a-c undergo oxidative ring cleavage to afford 2-benzoyloxyphenylglyoxylic acids 2a-c, whereas the substrates 1d-f result in the formation of acids 2d-f alongwith 3d-f.

Krishna Nand Singh* & Rajesh Kumar

Authors for correspondence are indicated by (*)